*       array. This hashing API accepts an arbitrary sequence of byte and multibyte values (via
 *       {@link Hasher}), but this is merely a convenience; these are always translated into raw
 *       byte sequences under the covers.
 *   <li><b>hash code:</b> each hash function always yields hash codes of the same fixed bit length
 *       (given by {@link #bits}). For example, {@link Hashing#sha1} produces a 160-bit number,

        Hashing.md5().bits() + Hashing.md5().bits(),
        Hashing.concatenating(Hashing.md5(), Hashing.md5()).bits());
    assertEquals(
        Hashing.md5().bits() + Hashing.murmur3_32().bits(),
        Hashing.concatenating(Hashing.md5(), Hashing.murmur3_32()).bits());
    assertEquals(
        Hashing.md5().bits() + Hashing.murmur3_32().bits() + Hashing.murmur3_128().bits(),

  }

  public void testHashCode_equalsAndSerializable() throws Exception {
    sanityTester().testEqualsAndSerializable();
  }

  public void testRoundTripHashCodeUsingBaseEncoding() {
    HashCode hash1 = Hashing.sha1().hashString("foo", Charsets.US_ASCII);
    HashCode hash2 = HashCode.fromBytes(BaseEncoding.base16().lowerCase().decode(hash1.toString()));
    assertEquals(hash1, hash2);
  }

  public void testObjectHashCode() {

    String init = "d41d8cd98f00b204e9800998ecf8427e";
    assertEquals(init, Hashing.md5().newHasher().hash().toString());

    String asciiHash = "e5df5a39f2b8cb71b24e1d8038f93131";
    assertEquals(asciiHash, Files.hash(asciiFile, Hashing.md5()).toString());

    String i18nHash = "7fa826962ce2079c8334cd4ebf33aea4";
    assertEquals(i18nHash, Files.hash(i18nFile, Hashing.md5()).toString());
  }

  public void testMap() throws IOException {

import com.google.common.base.Charsets;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import com.google.common.hash.Hashing;
import com.google.common.io.Closer.LoggingSuppressor;
import com.google.common.primitives.UnsignedBytes;
import com.google.common.testing.TestLogHandler;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

   * can hold setSize elements with the desired load factor. Always returns at least setSize + 2.
   */
  // TODO(cpovirk): Move to Hashing or something, since it's used elsewhere in the Android version.
  static int chooseTableSize(int setSize) {
    setSize = Math.max(setSize, 2);
    // Correct the size for open addressing to match desired load factor.

  private static FluentIterable<? extends Number> getSomeNumbers() {
    return FluentIterable.from(ImmutableList.<Number>of());
  }

  /*
   * The following tests demonstrate the shortcomings of or() and test that the casting workaround
   * mentioned in the method Javadoc does in fact compile.
   */

  @SuppressWarnings("unused") // compilation test
  public void testSampleCodeError1() {

   * holds the lock. If a hashed slot is empty, and lock is
   * available, a new Cell is created. Otherwise, if the slot
   * exists, a CAS is tried.  Retries proceed by "double hashing",
   * using a secondary hash (Marsaglia XorShift) to try to find a
   * free slot.
   *
   * The table size is capped because, when there are more threads
   * than CPUs, supposing that each thread were bound to a CPU,

   * Number value = first.or(0.5); // error
   * }</pre>
   *
   * <p>As a workaround, it is always safe to cast an {@code Optional<? extends T>} to {@code
   * Optional<T>}. Casting either of the above example {@code Optional} instances to {@code
   * Optional<Number>} (where {@code Number} is the desired output type) solves the problem:
   *
   * <pre>{@code

 * reasonable and it will be fine.
 *
 * <ul>
 *   <li>If checking whether the <i>caller</i> has violated your method or constructor's contract
 *       (such as by passing an invalid argument), use the utilities of the {@link Preconditions}
 *       class instead.
 *   <li>If checking an <i>impossible</i> condition (which <i>cannot</i> happen unless your own