*
   * <p>The returned set isn't threadsafe or serializable, even if {@code unfiltered} is.
   *
   * <p>Many of the filtered set's methods, such as {@code size()}, iterate across every element in
   * the underlying set and determine which elements satisfy the filter. When a live view is
   * <i>not</i> needed, it may be faster to copy {@code Iterables.filter(unfiltered, predicate)} and
   * use the copy.

      while (iterator.hasNext()) {
        if (element.equals(iterator.next())) {
          return true;
        }
      }
    }
    return false;
  }

  /**
   * Traverses an iterator and removes every element that belongs to the provided collection. The
   * iterator will be left exhausted: its {@code hasNext()} method will return {@code false}.
   *
   * @param removeFrom the iterator to (potentially) remove elements from

      while (iterator.hasNext()) {
        if (element.equals(iterator.next())) {
          return true;
        }
      }
    }
    return false;
  }

  /**
   * Traverses an iterator and removes every element that belongs to the provided collection. The
   * iterator will be left exhausted: its {@code hasNext()} method will return {@code false}.
   *
   * @param removeFrom the iterator to (potentially) remove elements from

   *       exceptions).
   * </ul>
   *
   * <p>The overall principle is to continue to treat every checked exception as a checked
   * exception, every unchecked exception as an unchecked exception, and every error as an error. In
   * addition, the cause of any {@code ExecutionException} is wrapped in order to ensure that the
   * new stack trace matches that of the current thread.

   * underlying multimap.
   *
   * <p>The returned multimap isn't threadsafe or serializable, even if {@code unfiltered} is.
   *
   * <p>Many of the filtered multimap's methods, such as {@code size()}, iterate across every
   * key/value mapping in the underlying multimap and determine which satisfy the filter. When a
   * live view is <i>not</i> needed, it may be faster to copy the filtered multimap and use the
   * copy.
   *

      if ((readCount.incrementAndGet() & DRAIN_THRESHOLD) == 0) {
        runCleanup();
      }
    }

    /**
     * Performs routine cleanup prior to executing a write. This should be called every time a write
     * thread acquires the segment lock, immediately after acquiring the lock.
     */
    @GuardedBy("this")
    void preWriteCleanup() {
      runLockedCleanup();
    }

              // this has 2 benefits
              // 1. for long chains of futures strung together with setFuture we consume less stack
              // 2. we avoid allocating Cancellation objects at every level of the cancellation
              //    chain
              // We can only do this for TrustedFuture, because TrustedFuture.cancel is final and
              // does nothing but delegate to this method.

   * character, until this returns {@code false} or the end is reached.
   *
   * @param sequence the character sequence to examine, possibly empty
   * @return {@code true} if this matcher matches every character in the sequence, including when
   *     the sequence is empty
   */
  public boolean matchesAllOf(CharSequence sequence) {
    for (int i = sequence.length() - 1; i >= 0; i--) {

 * environment if possible) before spending a lot of effort on tweaking a particular element.
 *
 * <h3>Other types of preconditions</h3>
 *
 * <p>Not every type of precondition failure is supported by these methods. Continue to throw
 * standard JDK exceptions such as {@link java.util.NoSuchElementException} or {@link
 * UnsupportedOperationException} in the situations they are intended for.

 * environment if possible) before spending a lot of effort on tweaking a particular element.
 *
 * <h3>Other types of preconditions</h3>
 *
 * <p>Not every type of precondition failure is supported by these methods. Continue to throw
 * standard JDK exceptions such as {@link java.util.NoSuchElementException} or {@link
 * UnsupportedOperationException} in the situations they are intended for.