for (HashCode hashCode : hashCodes) {
      byte[] nextBytes = hashCode.asBytes();
      checkArgument(
          nextBytes.length == resultBytes.length, "All hashcodes must have the same bit length.");
      for (int i = 0; i < nextBytes.length; i++) {
        resultBytes[i] = (byte) (resultBytes[i] * 37 ^ nextBytes[i]);
      }
    }
    return HashCode.fromBytesNoCopy(resultBytes);
  }

        expect:
        weakKey1 == weakKey2
    }

    def "hashCode of weakKey is system identity hashCode"() {
        Thing thing = new Thing("thing")
        WeakIdentityHashMap.WeakKey<Thing> weakKey = new WeakIdentityHashMap.WeakKey<>(thing)

        expect:
        weakKey.hashCode() == System.identityHashCode(thing)
    }

    class Thing {
        String name

    byte[] col3 = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, (byte) 0xff};

    ImmutableSet<HashCode> hashCodes =
        ImmutableSet.of(
            SIP_WITH_KEY.hashBytes(col1),
            SIP_WITH_KEY.hashBytes(col2),
            SIP_WITH_KEY.hashBytes(col3));
    assertEquals(3, hashCodes.size());
  }

  public void testToString() {

    private static final HashCode NO_HASH = Hashing.signature(CachingResourceHasher.class.getName() + " : no hash");
    private final IndexedCache<HashCode, HashCode> indexedCache;

    public DefaultResourceSnapshotterCacheService(IndexedCache<HashCode, HashCode> indexedCache) {
        this.indexedCache = indexedCache;
    }

    @Nullable
    @Override

import org.gradle.internal.hash.HashCode;

public class DefaultBuildCacheKey implements BuildCacheKeyInternal {
    private final HashCode hashCode;

    public DefaultBuildCacheKey(HashCode hashCode) {
        this.hashCode = hashCode;
    }

    @Override
    public String getHashCode() {
        return hashCode.toString();
    }

    @Override
    public HashCode getHashCodeInternal() {

package org.gradle.caching.internal;

import org.gradle.internal.hash.HashCode;

public class SimpleBuildCacheKey implements BuildCacheKeyInternal {
    private final HashCode hashCode;

    public SimpleBuildCacheKey(HashCode hashCode) {
        this.hashCode = hashCode;
    }

    @Override
    public HashCode getHashCodeInternal() {
        return hashCode;
    }

    @Override
    public String getHashCode() {

import org.gradle.internal.hash.HashCode
import org.gradle.internal.hash.TestHashCodes

class TestBuildCacheKey implements BuildCacheKeyInternal {
    private final HashCode hashCode

    TestBuildCacheKey(long hashCode) {
        this(TestHashCodes.hashCodeFrom(hashCode))
    }

    TestBuildCacheKey(HashCode hashCode) {
        this.hashCode = hashCode
    }

    @Override
    String getHashCode() {

            @Nullable
            @Override
            HashCode handle(RegularFileSnapshot fileSnapshot, IoFunction<RegularFileSnapshot, HashCode> function) throws IOException {
                return function.apply(fileSnapshot);
            }

            @Nullable
            @Override
            HashCode handle(ZipEntryContent zipEntry, IoFunction<ZipEntryContent, HashCode> function) throws IOException {

        hash = hash * 31 + (plugin.isExtensions() ? 1 : 0);

        for (Dependency dependency : plugin.getDependencies()) {
            hash = hash * 31 + Objects.hashCode(dependency.getGroupId());
            hash = hash * 31 + Objects.hashCode(dependency.getArtifactId());
            hash = hash * 31 + Objects.hashCode(dependency.getVersion());
            hash = hash * 31 + Objects.hashCode(dependency.getType());

        this.isEquivalentToForce = isEquivalentToForce;
        if (hasCustomDescription) {
            this.hashCode = 31 * (31 * cause.hashCode() + description.hashCode()) + (isEquivalentToForce ? 1 : 0);
        } else {
            this.hashCode = 31 * cause.hashCode() + (isEquivalentToForce ? 1 : 0);
        }
    }

    @Override
    public ComponentSelectionCause getCause() {
        return cause;