* following three expressions all generate colliding hash codes:
 *
 * <pre>{@code
 * newHasher().putByte(b1).putByte(b2).putByte(b3).hash()
 * newHasher().putByte(b1).putBytes(new byte[] { b2, b3 }).hash()
 * newHasher().putBytes(new byte[] { b1, b2, b3 }).hash()
 * }</pre>
 *
 * <p>If you wish to avoid this, you should either prepend or append the size of each chunk. Keep in

        itemInfo,
        relatedInfo,
        equivalence.equivalent(item, related));

    int itemHash = equivalence.hash(item);
    int relatedHash = equivalence.hash(related);
    assertWithTemplate(
        "the $HASH ("
            + itemHash
            + ") of $ITEM must be equal to the $HASH ("
            + relatedHash
            + ") of $OTHER",
        itemInfo,
        relatedInfo,

          distribution: 'zulu'
          cache: 'maven'
      - name: 'Install'
        shell: bash
        run: ./mvnw -B -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=warn install -U -DskipTests=true -f $ROOT_POM
      - name: 'Test'
        shell: bash
        run: ./mvnw -B -P!standard-with-extra-repos verify -U -Dmaven.javadoc.skip=true -f $ROOT_POM

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.CharMatcher.NamedFastMatcher;
import java.util.BitSet;

/**
 * An immutable version of CharMatcher for smallish sets of characters that uses a hash table with
 * linear probing to check for matches.
 *
 * @author Christopher Swenson
 */
@GwtIncompatible // no precomputation is done in GWT
@ElementTypesAreNonnullByDefault

      checkNotDone();
      digest.update(bytes);
    }

    private void checkNotDone() {
      checkState(!done, "Cannot re-use a Hasher after calling hash() on it");
    }

    @Override
    public HashCode hash() {
      checkNotDone();
      done = true;
      return (bytes == digest.getDigestLength())
          ? HashCode.fromBytesNoCopy(digest.digest())

 * constant time operations. Expected in the hashtable sense (depends on the hash function doing a
 * good job of distributing the elements to the buckets to a distribution not far from uniform), and
 * amortized since some operations can trigger a hash table resize.
 *
 * <p>This implementation consumes significantly less memory than {@code java.util.LinkedHashSet} or

 * amortized) constant time operations. Expected in the hashtable sense (depends on the hash
 * function doing a good job of distributing the elements to the buckets to a distribution not far
 * from uniform), and amortized since some operations can trigger a hash table resize.
 *
 * <p>As compared with {@link java.util.LinkedHashMap}, this structure places significantly reduced

import static org.junit.Assert.assertThrows;

import com.google.common.base.Charsets;
import com.google.common.base.Optional;
import com.google.common.collect.ImmutableList;
import com.google.common.hash.HashCode;
import com.google.common.hash.Hashing;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * Implementation of ImmutableMap backed by a JDK HashMap, which has smartness protecting against
 * hash flooding.
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
final class JdkBackedImmutableMap<K, V> extends ImmutableMap<K, V> {
  /**
   * Creates an {@code ImmutableMap} backed by a JDK HashMap. Used when probable hash flooding is

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.SampleElements.Colliders;
import java.util.List;

/**
 * A generator using sample elements whose hash codes all collide badly.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class TestCollidingSetGenerator implements TestSetGenerator<Object> {
  @Override