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	/*
	* Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.lang.annotation;

	/**
	* The common interface extended by all annotation interfaces. Note that an
	* interface that manually extends this one does <i>not</i> define
	* an annotation interface. Also note that this interface does not itself
	* define an annotation interface.
	*
	* More information about annotation interfaces can be found in section
	* {@jls 9.6} of <cite>The Java Language Specification</cite>.
	*
	* The {@link java.lang.reflect.AnnotatedElement} interface discusses
	* compatibility concerns when evolving an annotation interface from being
	* non-repeatable to being repeatable.
	*
	* @author Josh Bloch
	* @since 1.5
	*/
	public interface Annotation {
	/**
	* Returns true if the specified object represents an annotation
	* that is logically equivalent to this one. In other words,
	* returns true if the specified object is an instance of the same
	* annotation interface as this instance, all of whose members are equal
	* to the corresponding member of this annotation, as defined below:
	* <ul>
	* <li>Two corresponding primitive typed members whose values are
	* {@code x} and {@code y} are considered equal if {@code x == y},
	* unless their type is {@code float} or {@code double}.
	*
	* <li>Two corresponding {@code float} members whose values
	* are {@code x} and {@code y} are considered equal if
	* {@code Float.valueOf(x).equals(Float.valueOf(y))}.
	* (Unlike the {@code ==} operator, NaN is considered equal
	* to itself, and {@code 0.0f} unequal to {@code -0.0f}.)
	*
	* <li>Two corresponding {@code double} members whose values
	* are {@code x} and {@code y} are considered equal if
	* {@code Double.valueOf(x).equals(Double.valueOf(y))}.
	* (Unlike the {@code ==} operator, NaN is considered equal
	* to itself, and {@code 0.0} unequal to {@code -0.0}.)
	*
	* <li>Two corresponding {@code String}, {@code Class}, enum, or
	* annotation typed members whose values are {@code x} and {@code y}
	* are considered equal if {@code x.equals(y)}. (Note that this
	* definition is recursive for annotation typed members.)
	*
	* <li>Two corresponding array typed members {@code x} and {@code y}
	* are considered equal if {@code Arrays.equals(x, y)}, for the
	* appropriate overloading of {@link java.util.Arrays#equals Arrays.equals}.
	* </ul>
	*
	* @return true if the specified object represents an annotation
	* that is logically equivalent to this one, otherwise false
	*/
	boolean equals(Object obj);

	/**
	* Returns the hash code of this annotation.
	*
	* <p>The hash code of an annotation is the sum of the hash codes
	* of its members (including those with default values).
	*
	* The hash code of an annotation member is (127 times the hash code
	* of the member-name as computed by {@link String#hashCode()}) XOR
	* the hash code of the member-value.
	* The hash code of a member-value depends on its type as defined below:
	* <ul>
	* <li>The hash code of a primitive value <i>{@code v}</i> is equal to
	* <code><i>WrapperType</i>.valueOf(<i>v</i>).hashCode()</code>, where
	* <i>{@code WrapperType}</i> is the wrapper type corresponding
	* to the primitive type of <i>{@code v}</i> ({@link Byte},
	* {@link Character}, {@link Double}, {@link Float}, {@link Integer},
	* {@link Long}, {@link Short}, or {@link Boolean}).
	*
	* <li>The hash code of a string, enum, class, or annotation member-value
	* <i>{@code v}</i> is computed as by calling
	* <code><i>v</i>.hashCode()</code>. (In the case of annotation
	* member values, this is a recursive definition.)
	*
	* <li>The hash code of an array member-value is computed by calling
	* the appropriate overloading of
	* {@link java.util.Arrays#hashCode(long[]) Arrays.hashCode}
	* on the value. (There is one overloading for each primitive
	* type, and one for object reference types.)
	* </ul>
	*
	* @return the hash code of this annotation
	*/
	int hashCode();

	/**
	* Returns a string representation of this annotation. The details
	* of the representation are implementation-dependent, but the following
	* may be regarded as typical:
	* <pre>
	* @com.example.Name(first="Duke", middle="of", last="Java")
	* </pre>
	*
	* @return a string representation of this annotation
	*/
	String toString();

	/**
	* Returns the annotation interface of this annotation.
	*
	* @apiNote Implementation-dependent classes are used to provide
	* the implementations of annotations. Therefore, calling {@link
	* Object#getClass getClass} on an annotation will return an
	* implementation-dependent class. In contrast, this method will
	* reliably return the annotation interface of the annotation.
	*
	* @return the annotation interface of this annotation
	* @see Enum#getDeclaringClass
	*/
	Class<? extends Annotation> annotationType();
	}

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