* of several definitions of "whitespace"</a>.)
   *
   * <p>All Unicode White_Space characters are on the BMP and thus supported by this API.
   *
   * <p><b>Note:</b> as the Unicode definition evolves, we will modify this matcher to keep it up to
   * date.
   *
   * @since 19.0 (since 1.0 as constant {@code WHITESPACE})
   */
  public static CharMatcher whitespace() {
    return Whitespace.INSTANCE;
  }

  //
  // For the time being we are OK with the problem discussed above since it requires a caller to
  // introduce a very specific kind of data-race. And given the other operations performed by these
  // methods that involve volatile read/write operations, in practice there is no issue. Also, the
  // way in such a visibility issue would surface is most likely as a failure of cancel() to

      return builder.build();
    }

    /**
     * Copies the current contents of this set view into an existing set. This method has equivalent
     * behavior to {@code set.addAll(this)}, assuming that all the sets involved are based on the
     * same notion of equivalence.
     *
     * @return a reference to {@code set}, for convenience
     */
    // Note: S should logically extend Set<? super E> but can't due to either

    general mechanism. The dispatcher now exposes all in-flight calls via its
    `runningCalls()` and `queuedCalls()` methods. You can write code that
    selects calls by tag, host, or whatever, and invokes `Call.cancel()` on the
    ones that are no longer necessary.

 *  **OkHttp no longer uses the global `java.net.Authenticator` by default.**
    We've changed our `Authenticator` interface to authenticate web and proxy