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	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package org.apache.commons.lang3.builder;

	import java.lang.reflect.AccessibleObject;
	import java.lang.reflect.Field;
	import java.lang.reflect.Modifier;
	import java.util.Arrays;
	import java.util.Collection;
	import java.util.Comparator;
	import java.util.HashSet;
	import java.util.Set;

	import org.apache.commons.lang3.ArrayUtils;
	import org.apache.commons.lang3.Validate;

	/**
	* <p>
	* Assists in implementing {@link Object#hashCode()} methods.
	* </p>
	*
	* <p>
	* This class enables a good {@code hashCode} method to be built for any class. It follows the rules laid out in
	* the book <a href="http://www.oracle.com/technetwork/java/effectivejava-136174.html">Effective Java</a> by Joshua Bloch. Writing a
	* good {@code hashCode} method is actually quite difficult. This class aims to simplify the process.
	* </p>
	*
	* <p>
	* The following is the approach taken. When appending a data field, the current total is multiplied by the
	* multiplier then a relevant value
	* for that data type is added. For example, if the current hashCode is 17, and the multiplier is 37, then
	* appending the integer 45 will create a hash code of 674, namely 17 * 37 + 45.
	* </p>
	*
	* <p>
	* All relevant fields from the object should be included in the {@code hashCode} method. Derived fields may be
	* excluded. In general, any field used in the {@code equals} method must be used in the {@code hashCode}
	* method.
	* </p>
	*
	* <p>
	* To use this class write code as follows:
	* </p>
	*
	* <pre>
	* public class Person {
	* String name;
	* int age;
	* boolean smoker;
	* ...
	*
	* public int hashCode() {
	* // you pick a hard-coded, randomly chosen, non-zero, odd number
	* // ideally different for each class
	* return new HashCodeBuilder(17, 37).
	* append(name).
	* append(age).
	* append(smoker).
	* toHashCode();
	* }
	* }
	* </pre>
	*
	* <p>
	* If required, the superclass {@code hashCode()} can be added using {@link #appendSuper}.
	* </p>
	*
	* <p>
	* Alternatively, there is a method that uses reflection to determine the fields to test. Because these fields are
	* usually private, the method, {@code reflectionHashCode}, uses {@code AccessibleObject.setAccessible}
	* to change the visibility of the fields. This will fail under a security manager, unless the appropriate permissions
	* are set up correctly. It is also slower than testing explicitly.
	* </p>
	*
	* <p>
	* A typical invocation for this method would look like:
	* </p>
	*
	* <pre>
	* public int hashCode() {
	* return HashCodeBuilder.reflectionHashCode(this);
	* }
	* </pre>
	*
	* <p>The {@link HashCodeExclude} annotation can be used to exclude fields from being
	* used by the {@code reflectionHashCode} methods.</p>
	*
	* @since 1.0
	*/
	public class HashCodeBuilder implements Builder<Integer> {
	/**
	* The default initial value to use in reflection hash code building.
	*/
	private static final int DEFAULT_INITIAL_VALUE = 17;

	/**
	* The default multiplier value to use in reflection hash code building.
	*/
	private static final int DEFAULT_MULTIPLIER_VALUE = 37;

	/**
	* <p>
	* A registry of objects used by reflection methods to detect cyclical object references and avoid infinite loops.
	* </p>
	*
	* @since 2.3
	*/
	private static final ThreadLocal<Set<IDKey>> REGISTRY = new ThreadLocal<>();

	/*
	* NOTE: we cannot store the actual objects in a HashSet, as that would use the very hashCode()
	* we are in the process of calculating.
	*
	* So we generate a one-to-one mapping from the original object to a new object.
	*
	* Now HashSet uses equals() to determine if two elements with the same hash code really
	* are equal, so we also need to ensure that the replacement objects are only equal
	* if the original objects are identical.
	*
	* The original implementation (2.4 and before) used the System.identityHashCode()
	* method - however this is not guaranteed to generate unique ids (e.g. LANG-459)
	*
	* We now use the IDKey helper class (adapted from org.apache.axis.utils.IDKey)
	* to disambiguate the duplicate ids.
	*/

	/**
	* <p>
	* Returns the registry of objects being traversed by the reflection methods in the current thread.
	* </p>
	*
	* @return Set the registry of objects being traversed
	* @since 2.3
	*/
	static Set<IDKey> getRegistry() {
	return REGISTRY.get();
	}

	/**
	* <p>
	* Returns {@code true} if the registry contains the given object. Used by the reflection methods to avoid
	* infinite loops.
	* </p>
	*
	* @param value
	* The object to lookup in the registry.
	* @return boolean {@code true} if the registry contains the given object.
	* @since 2.3
	*/
	static boolean isRegistered(final Object value) {
	final Set<IDKey> registry = getRegistry();
	return registry != null && registry.contains(new IDKey(value));
	}

	/**
	* <p>
	* Appends the fields and values defined by the given object of the given {@code Class}.
	* </p>
	*
	* @param object
	* the object to append details of
	* @param clazz
	* the class to append details of
	* @param builder
	* the builder to append to
	* @param useTransients
	* whether to use transient fields
	* @param excludeFields
	* Collection of String field names to exclude from use in calculation of hash code
	*/
	private static void reflectionAppend(final Object object, final Class<?> clazz, final HashCodeBuilder builder, final boolean useTransients,
	final String[] excludeFields) {
	if (isRegistered(object)) {
	return;
	}
	try {
	register(object);
	// The elements in the returned array are not sorted and are not in any particular order.
	final Field[] fields = clazz.getDeclaredFields();
	Arrays.sort(fields, Comparator.comparing(Field::getName));
	AccessibleObject.setAccessible(fields, true);
	for (final Field field : fields) {
	if (!ArrayUtils.contains(excludeFields, field.getName())
	&& !field.getName().contains("$")
	&& (useTransients \|\| !Modifier.isTransient(field.getModifiers()))
	&& !Modifier.isStatic(field.getModifiers())
	&& !field.isAnnotationPresent(HashCodeExclude.class)) {
	try {
	final Object fieldValue = field.get(object);
	builder.append(fieldValue);
	} catch (final IllegalAccessException e) {
	// this can't happen. Would get a Security exception instead
	// throw a runtime exception in case the impossible happens.
	throw new InternalError("Unexpected IllegalAccessException");
	}
	}
	}
	} finally {
	unregister(object);
	}
	}

	/**
	* <p>
	* Uses reflection to build a valid hash code from the fields of {@code object}.
	* </p>
	*
	* <p>
	* It uses {@code AccessibleObject.setAccessible} to gain access to private fields. This means that it will
	* throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
	* also not as efficient as testing explicitly.
	* </p>
	*
	* <p>
	* Transient members will be not be used, as they are likely derived fields, and not part of the value of the
	* {@code Object}.
	* </p>
	*
	* <p>
	* Static fields will not be tested. Superclass fields will be included.
	* </p>
	*
	* <p>
	* Two randomly chosen, non-zero, odd numbers must be passed in. Ideally these should be different for each class,
	* however this is not vital. Prime numbers are preferred, especially for the multiplier.
	* </p>
	*
	* @param initialNonZeroOddNumber
	* a non-zero, odd number used as the initial value. This will be the returned
	* value if no fields are found to include in the hash code
	* @param multiplierNonZeroOddNumber
	* a non-zero, odd number used as the multiplier
	* @param object
	* the Object to create a {@code hashCode} for
	* @return int hash code
	* @throws IllegalArgumentException
	* if the Object is {@code null}
	* @throws IllegalArgumentException
	* if the number is zero or even
	*
	* @see HashCodeExclude
	*/
	public static int reflectionHashCode(final int initialNonZeroOddNumber, final int multiplierNonZeroOddNumber, final Object object) {
	return reflectionHashCode(initialNonZeroOddNumber, multiplierNonZeroOddNumber, object, false, null);
	}

	/**
	* <p>
	* Uses reflection to build a valid hash code from the fields of {@code object}.
	* </p>
	*
	* <p>
	* It uses {@code AccessibleObject.setAccessible} to gain access to private fields. This means that it will
	* throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
	* also not as efficient as testing explicitly.
	* </p>
	*
	* <p>
	* If the TestTransients parameter is set to {@code true}, transient members will be tested, otherwise they
	* are ignored, as they are likely derived fields, and not part of the value of the {@code Object}.
	* </p>
	*
	* <p>
	* Static fields will not be tested. Superclass fields will be included.
	* </p>
	*
	* <p>
	* Two randomly chosen, non-zero, odd numbers must be passed in. Ideally these should be different for each class,
	* however this is not vital. Prime numbers are preferred, especially for the multiplier.
	* </p>
	*
	* @param initialNonZeroOddNumber
	* a non-zero, odd number used as the initial value. This will be the returned
	* value if no fields are found to include in the hash code
	* @param multiplierNonZeroOddNumber
	* a non-zero, odd number used as the multiplier
	* @param object
	* the Object to create a {@code hashCode} for
	* @param testTransients
	* whether to include transient fields
	* @return int hash code
	* @throws IllegalArgumentException
	* if the Object is {@code null}
	* @throws IllegalArgumentException
	* if the number is zero or even
	*
	* @see HashCodeExclude
	*/
	public static int reflectionHashCode(final int initialNonZeroOddNumber, final int multiplierNonZeroOddNumber, final Object object,
	final boolean testTransients) {
	return reflectionHashCode(initialNonZeroOddNumber, multiplierNonZeroOddNumber, object, testTransients, null);
	}

	/**
	* <p>
	* Uses reflection to build a valid hash code from the fields of {@code object}.
	* </p>
	*
	* <p>
	* It uses {@code AccessibleObject.setAccessible} to gain access to private fields. This means that it will
	* throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
	* also not as efficient as testing explicitly.
	* </p>
	*
	* <p>
	* If the TestTransients parameter is set to {@code true}, transient members will be tested, otherwise they
	* are ignored, as they are likely derived fields, and not part of the value of the {@code Object}.
	* </p>
	*
	* <p>
	* Static fields will not be included. Superclass fields will be included up to and including the specified
	* superclass. A null superclass is treated as java.lang.Object.
	* </p>
	*
	* <p>
	* Two randomly chosen, non-zero, odd numbers must be passed in. Ideally these should be different for each class,
	* however this is not vital. Prime numbers are preferred, especially for the multiplier.
	* </p>
	*
	* @param <T>
	* the type of the object involved
	* @param initialNonZeroOddNumber
	* a non-zero, odd number used as the initial value. This will be the returned
	* value if no fields are found to include in the hash code
	* @param multiplierNonZeroOddNumber
	* a non-zero, odd number used as the multiplier
	* @param object
	* the Object to create a {@code hashCode} for
	* @param testTransients
	* whether to include transient fields
	* @param reflectUpToClass
	* the superclass to reflect up to (inclusive), may be {@code null}
	* @param excludeFields
	* array of field names to exclude from use in calculation of hash code
	* @return int hash code
	* @throws IllegalArgumentException
	* if the Object is {@code null}
	* @throws IllegalArgumentException
	* if the number is zero or even
	*
	* @see HashCodeExclude
	* @since 2.0
	*/
	public static <T> int reflectionHashCode(final int initialNonZeroOddNumber, final int multiplierNonZeroOddNumber, final T object,
	final boolean testTransients, final Class<? super T> reflectUpToClass, final String... excludeFields) {
	Validate.notNull(object, "The object to build a hash code for must not be null");
	final HashCodeBuilder builder = new HashCodeBuilder(initialNonZeroOddNumber, multiplierNonZeroOddNumber);
	Class<?> clazz = object.getClass();
	reflectionAppend(object, clazz, builder, testTransients, excludeFields);
	while (clazz.getSuperclass() != null && clazz != reflectUpToClass) {
	clazz = clazz.getSuperclass();
	reflectionAppend(object, clazz, builder, testTransients, excludeFields);
	}
	return builder.toHashCode();
	}

	/**
	* <p>
	* Uses reflection to build a valid hash code from the fields of {@code object}.
	* </p>
	*
	* <p>
	* This constructor uses two hard coded choices for the constants needed to build a hash code.
	* </p>
	*
	* <p>
	* It uses {@code AccessibleObject.setAccessible} to gain access to private fields. This means that it will
	* throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
	* also not as efficient as testing explicitly.
	* </p>
	*
	* <P>
	* If the TestTransients parameter is set to {@code true}, transient members will be tested, otherwise they
	* are ignored, as they are likely derived fields, and not part of the value of the {@code Object}.
	* </p>
	*
	* <p>
	* Static fields will not be tested. Superclass fields will be included. If no fields are found to include
	* in the hash code, the result of this method will be constant.
	* </p>
	*
	* @param object
	* the Object to create a {@code hashCode} for
	* @param testTransients
	* whether to include transient fields
	* @return int hash code
	* @throws IllegalArgumentException
	* if the object is {@code null}
	*
	* @see HashCodeExclude
	*/
	public static int reflectionHashCode(final Object object, final boolean testTransients) {
	return reflectionHashCode(DEFAULT_INITIAL_VALUE, DEFAULT_MULTIPLIER_VALUE, object,
	testTransients, null);
	}

	/**
	* <p>
	* Uses reflection to build a valid hash code from the fields of {@code object}.
	* </p>
	*
	* <p>
	* This constructor uses two hard coded choices for the constants needed to build a hash code.
	* </p>
	*
	* <p>
	* It uses {@code AccessibleObject.setAccessible} to gain access to private fields. This means that it will
	* throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
	* also not as efficient as testing explicitly.
	* </p>
	*
	* <p>
	* Transient members will be not be used, as they are likely derived fields, and not part of the value of the
	* {@code Object}.
	* </p>
	*
	* <p>
	* Static fields will not be tested. Superclass fields will be included. If no fields are found to include
	* in the hash code, the result of this method will be constant.
	* </p>
	*
	* @param object
	* the Object to create a {@code hashCode} for
	* @param excludeFields
	* Collection of String field names to exclude from use in calculation of hash code
	* @return int hash code
	* @throws IllegalArgumentException
	* if the object is {@code null}
	*
	* @see HashCodeExclude
	*/
	public static int reflectionHashCode(final Object object, final Collection<String> excludeFields) {
	return reflectionHashCode(object, ReflectionToStringBuilder.toNoNullStringArray(excludeFields));
	}

	// -------------------------------------------------------------------------

	/**
	* <p>
	* Uses reflection to build a valid hash code from the fields of {@code object}.
	* </p>
	*
	* <p>
	* This constructor uses two hard coded choices for the constants needed to build a hash code.
	* </p>
	*
	* <p>
	* It uses {@code AccessibleObject.setAccessible} to gain access to private fields. This means that it will
	* throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
	* also not as efficient as testing explicitly.
	* </p>
	*
	* <p>
	* Transient members will be not be used, as they are likely derived fields, and not part of the value of the
	* {@code Object}.
	* </p>
	*
	* <p>
	* Static fields will not be tested. Superclass fields will be included. If no fields are found to include
	* in the hash code, the result of this method will be constant.
	* </p>
	*
	* @param object
	* the Object to create a {@code hashCode} for
	* @param excludeFields
	* array of field names to exclude from use in calculation of hash code
	* @return int hash code
	* @throws IllegalArgumentException
	* if the object is {@code null}
	*
	* @see HashCodeExclude
	*/
	public static int reflectionHashCode(final Object object, final String... excludeFields) {
	return reflectionHashCode(DEFAULT_INITIAL_VALUE, DEFAULT_MULTIPLIER_VALUE, object, false,
	null, excludeFields);
	}

	/**
	* <p>
	* Registers the given object. Used by the reflection methods to avoid infinite loops.
	* </p>
	*
	* @param value
	* The object to register.
	*/
	private static void register(final Object value) {
	Set<IDKey> registry = getRegistry();
	if (registry == null) {
	registry = new HashSet<>();
	REGISTRY.set(registry);
	}
	registry.add(new IDKey(value));
	}

	/**
	* <p>
	* Unregisters the given object.
	* </p>
	*
	* <p>
	* Used by the reflection methods to avoid infinite loops.
	*
	* @param value
	* The object to unregister.
	* @since 2.3
	*/
	private static void unregister(final Object value) {
	final Set<IDKey> registry = getRegistry();
	if (registry != null) {
	registry.remove(new IDKey(value));
	if (registry.isEmpty()) {
	REGISTRY.remove();
	}
	}
	}

	/**
	* Constant to use in building the hashCode.
	*/
	private final int iConstant;

	/**
	* Running total of the hashCode.
	*/
	private int iTotal = 0;

	/**
	* <p>
	* Uses two hard coded choices for the constants needed to build a {@code hashCode}.
	* </p>
	*/
	public HashCodeBuilder() {
	iConstant = 37;
	iTotal = 17;
	}

	/**
	* <p>
	* Two randomly chosen, odd numbers must be passed in. Ideally these should be different for each class,
	* however this is not vital.
	* </p>
	*
	* <p>
	* Prime numbers are preferred, especially for the multiplier.
	* </p>
	*
	* @param initialOddNumber
	* an odd number used as the initial value
	* @param multiplierOddNumber
	* an odd number used as the multiplier
	* @throws IllegalArgumentException
	* if the number is even
	*/
	public HashCodeBuilder(final int initialOddNumber, final int multiplierOddNumber) {
	Validate.isTrue(initialOddNumber % 2 != 0, "HashCodeBuilder requires an odd initial value");
	Validate.isTrue(multiplierOddNumber % 2 != 0, "HashCodeBuilder requires an odd multiplier");
	iConstant = multiplierOddNumber;
	iTotal = initialOddNumber;
	}

	/**
	* <p>
	* Append a {@code hashCode} for a {@code boolean}.
	* </p>
	* <p>
	* This adds {@code 1} when true, and {@code 0} when false to the {@code hashCode}.
	* </p>
	* <p>
	* This is in contrast to the standard {@code java.lang.Boolean.hashCode} handling, which computes
	* a {@code hashCode} value of {@code 1231} for {@code java.lang.Boolean} instances
	* that represent {@code true} or {@code 1237} for {@code java.lang.Boolean} instances
	* that represent {@code false}.
	* </p>
	* <p>
	* This is in accordance with the <i>Effective Java</i> design.
	* </p>
	*
	* @param value
	* the boolean to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final boolean value) {
	iTotal = iTotal * iConstant + (value ? 0 : 1);
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for a {@code boolean} array.
	* </p>
	*
	* @param array
	* the array to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final boolean[] array) {
	if (array == null) {
	iTotal = iTotal * iConstant;
	} else {
	for (final boolean element : array) {
	append(element);
	}
	}
	return this;
	}

	// -------------------------------------------------------------------------

	/**
	* <p>
	* Append a {@code hashCode} for a {@code byte}.
	* </p>
	*
	* @param value
	* the byte to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final byte value) {
	iTotal = iTotal * iConstant + value;
	return this;
	}

	// -------------------------------------------------------------------------

	/**
	* <p>
	* Append a {@code hashCode} for a {@code byte} array.
	* </p>
	*
	* @param array
	* the array to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final byte[] array) {
	if (array == null) {
	iTotal = iTotal * iConstant;
	} else {
	for (final byte element : array) {
	append(element);
	}
	}
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for a {@code char}.
	* </p>
	*
	* @param value
	* the char to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final char value) {
	iTotal = iTotal * iConstant + value;
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for a {@code char} array.
	* </p>
	*
	* @param array
	* the array to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final char[] array) {
	if (array == null) {
	iTotal = iTotal * iConstant;
	} else {
	for (final char element : array) {
	append(element);
	}
	}
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for a {@code double}.
	* </p>
	*
	* @param value
	* the double to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final double value) {
	return append(Double.doubleToLongBits(value));
	}

	/**
	* <p>
	* Append a {@code hashCode} for a {@code double} array.
	* </p>
	*
	* @param array
	* the array to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final double[] array) {
	if (array == null) {
	iTotal = iTotal * iConstant;
	} else {
	for (final double element : array) {
	append(element);
	}
	}
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for a {@code float}.
	* </p>
	*
	* @param value
	* the float to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final float value) {
	iTotal = iTotal * iConstant + Float.floatToIntBits(value);
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for a {@code float} array.
	* </p>
	*
	* @param array
	* the array to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final float[] array) {
	if (array == null) {
	iTotal = iTotal * iConstant;
	} else {
	for (final float element : array) {
	append(element);
	}
	}
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for an {@code int}.
	* </p>
	*
	* @param value
	* the int to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final int value) {
	iTotal = iTotal * iConstant + value;
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for an {@code int} array.
	* </p>
	*
	* @param array
	* the array to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final int[] array) {
	if (array == null) {
	iTotal = iTotal * iConstant;
	} else {
	for (final int element : array) {
	append(element);
	}
	}
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for a {@code long}.
	* </p>
	*
	* @param value
	* the long to add to the {@code hashCode}
	* @return this
	*/
	// NOTE: This method uses >> and not >>> as Effective Java and
	// Long.hashCode do. Ideally we should switch to >>> at
	// some stage. There are backwards compat issues, so
	// that will have to wait for the time being. cf LANG-342.
	public HashCodeBuilder append(final long value) {
	iTotal = iTotal * iConstant + ((int) (value ^ (value >> 32)));
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for a {@code long} array.
	* </p>
	*
	* @param array
	* the array to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final long[] array) {
	if (array == null) {
	iTotal = iTotal * iConstant;
	} else {
	for (final long element : array) {
	append(element);
	}
	}
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for an {@code Object}.
	* </p>
	*
	* @param object
	* the Object to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final Object object) {
	if (object == null) {
	iTotal = iTotal * iConstant;

	} else {
	if (object.getClass().isArray()) {
	// factor out array case in order to keep method small enough
	// to be inlined
	appendArray(object);
	} else {
	iTotal = iTotal * iConstant + object.hashCode();
	}
	}
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for an array.
	* </p>
	*
	* @param object
	* the array to add to the {@code hashCode}
	*/
	private void appendArray(final Object object) {
	// 'Switch' on type of array, to dispatch to the correct handler
	// This handles multi dimensional arrays
	if (object instanceof long[]) {
	append((long[]) object);
	} else if (object instanceof int[]) {
	append((int[]) object);
	} else if (object instanceof short[]) {
	append((short[]) object);
	} else if (object instanceof char[]) {
	append((char[]) object);
	} else if (object instanceof byte[]) {
	append((byte[]) object);
	} else if (object instanceof double[]) {
	append((double[]) object);
	} else if (object instanceof float[]) {
	append((float[]) object);
	} else if (object instanceof boolean[]) {
	append((boolean[]) object);
	} else {
	// Not an array of primitives
	append((Object[]) object);
	}
	}

	/**
	* <p>
	* Append a {@code hashCode} for an {@code Object} array.
	* </p>
	*
	* @param array
	* the array to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final Object[] array) {
	if (array == null) {
	iTotal = iTotal * iConstant;
	} else {
	for (final Object element : array) {
	append(element);
	}
	}
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for a {@code short}.
	* </p>
	*
	* @param value
	* the short to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final short value) {
	iTotal = iTotal * iConstant + value;
	return this;
	}

	/**
	* <p>
	* Append a {@code hashCode} for a {@code short} array.
	* </p>
	*
	* @param array
	* the array to add to the {@code hashCode}
	* @return this
	*/
	public HashCodeBuilder append(final short[] array) {
	if (array == null) {
	iTotal = iTotal * iConstant;
	} else {
	for (final short element : array) {
	append(element);
	}
	}
	return this;
	}

	/**
	* <p>
	* Adds the result of super.hashCode() to this builder.
	* </p>
	*
	* @param superHashCode
	* the result of calling {@code super.hashCode()}
	* @return this HashCodeBuilder, used to chain calls.
	* @since 2.0
	*/
	public HashCodeBuilder appendSuper(final int superHashCode) {
	iTotal = iTotal * iConstant + superHashCode;
	return this;
	}

	/**
	* <p>
	* Returns the computed {@code hashCode}.
	* </p>
	*
	* @return {@code hashCode} based on the fields appended
	*/
	public int toHashCode() {
	return iTotal;
	}

	/**
	* Returns the computed {@code hashCode}.
	*
	* @return {@code hashCode} based on the fields appended
	*
	* @since 3.0
	*/
	@Override
	public Integer build() {
	return Integer.valueOf(toHashCode());
	}

	/**
	* <p>
	* The computed {@code hashCode} from toHashCode() is returned due to the likelihood
	* of bugs in mis-calling toHashCode() and the unlikeliness of it mattering what the hashCode for
	* HashCodeBuilder itself is.</p>
	*
	* @return {@code hashCode} based on the fields appended
	* @since 2.5
	*/
	@Override
	public int hashCode() {
	return toHashCode();
	}

	}

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