important to us to keep Guava as easy to use and understand as we can. That means boiling
        features down to compact but powerful abstractions, and controlling feature bloat carefully.


        Guava's main yardstick for evaluating proposed features can be summed up as [utility times
        ubiquity](https://github.com/google/guava/wiki/PhilosophyExplained#utility-times-ubiquity).


        #### Utility: compare with alternatives

 * unloading an OSGi bundle.
 *
 * <p>{@code com.google.common.base.FinalizableReferenceQueue} loads this class in its own class
 * loader. That way, this class doesn't prevent the main class loader from getting garbage
 * collected, and this class can detect when the main class loader has been garbage collected and
 * stop itself.
 */
// no @ElementTypesAreNonNullByDefault for the reasons discussed above
public class Finalizer implements Runnable {

      Adler32 checksum = new Adler32();
      checksum.update(testBytes, 0, testBytes.length);
      result = (byte) (result ^ checksum.getValue());
    }
    return result;
  }

  // Helpers + main

  private byte runHashFunction(int reps, HashFunction hashFunction) {
    byte result = 0x01;
    // Trick the JVM to prevent it from using the hash function non-polymorphically

            return hasher.hash().asBytes();
          }
        };
    // Murmur3F, MurmurHash3 for x64, 128-bit (MurmurHash3_x64_128)
    // From http://code.google.com/p/smhasher/source/browse/trunk/main.cpp
    HashTestUtils.verifyHashFunction(hf, 128, 0x6384BA69);
  }

  public void testInvariants() {
    HashTestUtils.assertInvariants(murmur3_128());
  }

      Adler32 checksum = new Adler32();
      checksum.update(testBytes, 0, testBytes.length);
      result = (byte) (result ^ checksum.getValue());
    }
    return result;
  }

  // Helpers + main

  private byte runHashFunction(int reps, HashFunction hashFunction) {
    byte result = 0x01;
    // Trick the JVM to prevent it from using the hash function non-polymorphically

     * impossible. We want the test, though, in case that changes in the future,
     * so we use isInstance instead.
     */
    assertFalse(
        "Can't test the main listenInPoolThread path "
            + "if the input is already a ListenableFuture",
        ListenableFuture.class.isInstance(input));
    ListenableFuture<String> listenable = listenInPoolThread(input);
    /*

 * unloading an OSGi bundle.
 *
 * <p>{@code com.google.common.base.FinalizableReferenceQueue} loads this class in its own class
 * loader. That way, this class doesn't prevent the main class loader from getting garbage
 * collected, and this class can detect when the main class loader has been garbage collected and
 * stop itself.
 */
// no @ElementTypesAreNonNullByDefault for the reasons discussed above
public class Finalizer implements Runnable {

    HashTestUtils.verifyHashFunction(hf, 32, 0xB0F57EE3);
  }

  public void testInvariants() {
    HashTestUtils.assertInvariants(murmur3_32());
  }

  @SuppressWarnings("deprecation")
  public void testInvalidUnicodeHashString() {
    String str =
        new String(
            new char[] {'a', Character.MIN_HIGH_SURROGATE, Character.MIN_HIGH_SURROGATE, 'z'});

  /*
   * Ideally, this class would have exposed only constructors that require a non-null cause. See
   * https://github.com/jspecify/jspecify-reference-checker/blob/61aafa4ae52594830cfc2d61c8b113009dbdb045/src/main/java/com/google/jspecify/nullness/NullSpecTransfer.java#L789
   * and https://github.com/jspecify/jspecify/issues/490.
   *
   * (Perhaps it should also have required that its cause was a RuntimeException. However, that