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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * The Universal Permissive License (UPL), Version 1.0
 *
 * Subject to the condition set forth below, permission is hereby granted to any
 * person obtaining a copy of this software, associated documentation and/or
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 * (a) the Software, and
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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
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package com.oracle.truffle.js.test.polyglot;

import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
import com.oracle.truffle.api.dsl.Fallback;
import com.oracle.truffle.api.dsl.Specialization;
import com.oracle.truffle.api.interop.InteropLibrary;
import com.oracle.truffle.api.interop.TruffleObject;
import com.oracle.truffle.api.library.ExportLibrary;
import com.oracle.truffle.api.library.ExportMessage;
import com.oracle.truffle.api.utilities.TriState;

Just a foreign null value.
/**
 * Just a foreign null value.
 */
@ExportLibrary(InteropLibrary.class)
public class ForeignNull implements TruffleObject {
    public ForeignNull() {
    }

    @SuppressWarnings("static-method")
    @ExportMessage
    final boolean isNull() {
        return true;
    }

    @ExportMessage
    static final class IsIdenticalOrUndefined {
        @Specialization
        static TriState doMyObject(ForeignNull receiver, ForeignNull other) {
            return TriState.valueOf(receiver == other);
        }

        @SuppressWarnings("unused")
        @Fallback
        static TriState doOther(ForeignNull receiver, Object other) {
            return TriState.UNDEFINED;
        }
    }

    @TruffleBoundary
    @ExportMessage
    final int identityHashCode() {
        return super.hashCode();
    }
}