@GwtCompatible
public enum MapFeature implements Feature<Map> {
  /**
   * The map does not throw {@code NullPointerException} on calls such as {@code containsKey(null)},
   * {@code get(null)}, {@code keySet().contains(null)} or {@code remove(null)}.
   */
  ALLOWS_NULL_KEY_QUERIES,
  ALLOWS_NULL_KEYS(ALLOWS_NULL_KEY_QUERIES),
  /**
   * The map does not throw {@code NullPointerException} on calls such as {@code

/kind documentation
/kind feature

Optionally add one or more of the following kinds if applicable:
/kind api-change
/kind deprecation
/kind failing-test
/kind flake
/kind regression
-->

#### What this PR does / why we need it:

#### Which issue(s) this PR is related to:
<!--
Please link relevant issues to help with tracking.

To automatically close the linked issue(s) when this PR is merged,

   * the XML specification.
   *
   * <p>This escaper does not escape non-ASCII characters to their numeric character references
   * (NCR). Any non-ASCII characters appearing in the input will be preserved in the output.
   * Specifically "\r" (carriage return) is preserved in the output, which may result in it being
   * silently converted to "\n" when the XML is parsed.
   *

     * @throws CurlException if the content does not exist.
     */
    public InputStream getContentAsStream() throws IOException {
        if (contentCache == null) {
            if (contentException != null) {
                throw new CurlException("The content does not exist.", contentException);
            } else {
                throw new CurlException("The content does not exist.");
            }
        }

     * @return An iterator of URL objects for the resources. If no resources are found, the iterator will be empty.
     *         Resources that the class loader does not have access to will not be included.
     * @see java.lang.ClassLoader#getResources(String)
     */
    public static Iterator<URL> getResources(final String name) {
        assertArgumentNotEmpty("name", name);

    // 'swallowException' when the mock does not throw an exception.
    setupCloseable(false);
    doClose(mockCloseable, false, false);

    setupCloseable(false);
    doClose(mockCloseable, true, false);
  }

  public void testClose_closeableWithEatenException() throws IOException {
    // make sure that no exception is thrown if 'swallowException' is true
    // when the mock does throw an exception.
    setupCloseable(true);

  static CharBuffer createBuffer() {
    return CharBuffer.allocate(DEFAULT_BUF_SIZE);
  }

  private CharStreams() {}

  /**
   * Copies all characters between the {@link Readable} and {@link Appendable} objects. Does not
   * close or flush either object.
   *
   * @param from the object to read from
   * @param to the object to write to
   * @return the number of characters copied
   * @throws IOException if an I/O error occurs

   * Stop the service. This method is invoked on the execution thread.
   *
   * <p>By default this method does nothing.
   */
  // TODO: consider supporting a TearDownTestCase-like API
  protected void shutDown() throws Exception {}

  /**
   * Invoked to request the service to stop.
   *
   * <p>By default this method does nothing.
   *

   *
   * <p>Like {@link BufferedReader#readLine()}, this method considers a line to be a sequence of
   * text that is terminated by (but does not include) one of {@code \r\n}, {@code \r} or {@code
   * \n}. If the source's content does not end in a line termination sequence, it is treated as if
   * it does.
   *
   * <p>The caller is responsible for ensuring that the returned stream is closed. For example:
   *
   * {@snippet :

   *
   * <p>Like {@link BufferedReader#readLine()}, this method considers a line to be a sequence of
   * text that is terminated by (but does not include) one of {@code \r\n}, {@code \r} or {@code
   * \n}. If the source's content does not end in a line termination sequence, it is treated as if
   * it does.
   *
   * <p>The caller is responsible for ensuring that the returned stream is closed. For example:
   *
   * {@snippet :