*   the first time in a method that nanoTime() has been invoked, for which the special value 0L
   *   is reserved to mean "uninitialized". If timeout is non-positive, then nanoTime need never be
   *   called.
   * - Keep behavior of fair and non-fair instances consistent.
   */

  /**
   * A boolean condition for which a thread may wait. A {@code Guard} is associated with a single

              // positive).
              bloomFilter.put(key);
              // False negative should *never* happen.
              assertThat(bloomFilter.mightContain(key)).isTrue();

              // If this check ever fails, that means we need to either bump the
              // number of expected insertions or don't run the test for so long.

        this.executor = executor;
      }

      void execute() {
        try {
          executor.execute(runnable);
        } catch (RuntimeException e) {
          log.log(
              Level.SEVERE,
              "RuntimeException while executing runnable "
                  + runnable
                  + " with executor "
                  + executor,
              e);
        }
      }
    }

 *       .result();
 * }
 * }</pre>
 *
 * <p>The value of this expression will have the same sign as the <i>first nonzero</i> comparison
 * result in the chain, or will be zero if every comparison result was zero.
 *
 * <p><b>Note:</b> {@code ComparisonChain} instances are <b>immutable</b>. For this utility to work
 * correctly, calls must be chained as illustrated above.
 *

  private void assertEntrySetNotContainsString(Set<Entry<K, V>> entrySet) {
    // Very unlikely that a buggy collection would ever return true. It might accidentally throw.
    assertFalse(entrySet.contains("foo"));
  }

  /**
   * Override this to check invariants which should hold true for a particular implementation, but
   * which are not generally applicable to every instance of Map.
   *

   * value for which {@link Comparable#compareTo(Object)} never returns a positive value for any
   * input of type {@code C}.
   *
   * <p>The default implementation throws {@code NoSuchElementException}.
   *
   * @return the minimum value of type {@code C}; never null
   * @throws NoSuchElementException if the type has no (practical) minimum value; for example,

      return Collections2.safeContains(collection, element);
    }
    return Iterators.contains(iterable.iterator(), element);
  }

  /**
   * Removes, from an iterable, every element that belongs to the provided collection.
   *
   * <p>This method calls {@link Collection#removeAll} if {@code iterable} is a collection, and
   * {@link Iterators#removeAll} otherwise.
   *

    @SuppressWarnings("UnnecessaryLambda") // Must be a fixed singleton object
    private static final Supplier<Void> SUCCESSFULLY_COMPUTED =
        () -> {
          throw new IllegalStateException(); // Should never get called.
        };

    private volatile Supplier<T> delegate;
    // "value" does not need to be volatile; visibility piggy-backs on volatile read of "delegate".
    @CheckForNull private T value;

        ALLOWS_NULL_KEYS);
  }

  /**
   * Map generator that verifies that {@code setUp()} methods are called in all the test cases. The
   * {@code setUpRan} parameter is set true by the {@code setUp} that every test case is supposed to
   * have registered, and set false by the {@code tearDown}. We use a dynamic proxy to intercept all
   * of the {@code Map} method calls and check that {@code setUpRan} is true.
   */

     * that users *can* pass null arguments to Joiner, we annotate it as if it always tolerates null
     * inputs, rather than as if it never tolerates them.
     *
     * We rely on checkers to implement special cases to catch dangerous calls to join(), etc. based
     * on what they know about the particular Joiner instances the calls are performed on.
     *