/** The HTTP {@code Accept-Language} header field name. */
  public static final String ACCEPT_LANGUAGE = "Accept-Language";
  /** The HTTP {@code Access-Control-Request-Headers} header field name. */
  public static final String ACCESS_CONTROL_REQUEST_HEADERS = "Access-Control-Request-Headers";
  /** The HTTP {@code Access-Control-Request-Method} header field name. */
  public static final String ACCESS_CONTROL_REQUEST_METHOD = "Access-Control-Request-Method";

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

/**
 * Utility methods and classes for I/O; for example input streams, output streams, readers, writers,
 * and files.
 *
 * <p>At the core of this package are the Source/Sink types: {@link ByteSource ByteSource}, {@link
 * CharSource CharSource}, {@link ByteSink ByteSink} and {@link CharSink CharSink}. They are

   *
   * <p>Why <i>not</i> just add {@code SuppressWarnings}? The problem is that this method is
   * typically useful for {@code return} statements. That leaves the code with two options: Either
   * add the suppression to the whole method (which turns off checking for a large section of code),
   * or extract a variable, and put the suppression on that. However, a local variable typically

   *       {@code consistentHash} will handle it. If, however, you are dividing traffic among
   *       servers {@code alpha}, {@code bravo}, and {@code charlie} and you occasionally need to
   *       take each of the servers offline, {@code consistentHash} will be a poor fit: It provides
   *       no way for you to specify which of the three buckets is disappearing. Thus, if your

   *
   * <p>Why <i>not</i> just add {@code SuppressWarnings}? The problem is that this method is
   * typically useful for {@code return} statements. That leaves the code with two options: Either
   * add the suppression to the whole method (which turns off checking for a large section of code),
   * or extract a variable, and put the suppression on that. However, a local variable typically

 *
 * <p>A call to any of the <i>enter</i> methods with <b>void</b> return type should always be
 * followed immediately by a <i>try/finally</i> block to ensure that the current thread leaves the
 * monitor cleanly:
 *
 * <pre>{@code
 * monitor.enter();
 * try {
 *   // do things while occupying the monitor
 * } finally {
 *   monitor.leave();
 * }
 * }</pre>
 *

seemed to rise like a stalk out of a sea of green leaves that lay
far below her.

  `What CAN all that green stuff be?' said Alice.  `And where
HAVE my shoulders got to?  And oh, my poor hands, how is it I
can't see you?'  She was moving them about as she spoke, but no
result seemed to follow, except a little shaking among the
distant green leaves.

  As there seemed to be no chance of getting her hands up to her

 *
 * <p>It is of course possible to use the methods of this class to check for invalid conditions
 * which are <i>not the caller's fault</i>. Doing so is <b>not recommended</b> because it is
 * misleading to future readers of the code and of stack traces. See <a
 * href="https://github.com/google/guava/wiki/ConditionalFailuresExplained">Conditional failures
 * explained</a> in the Guava User Guide for more advice. Notably, {@link Verify} offers assertions

/**
 * A {@link Reader} that concatenates multiple readers.
 *
 * @author Bin Zhu
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
class MultiReader extends Reader {
  private final Iterator<? extends CharSource> it;
  @CheckForNull private Reader current;

  MultiReader(Iterator<? extends CharSource> readers) throws IOException {
    this.it = readers;
    advance();
  }

   *
   * <p>Why <i>not</i> just add {@code SuppressWarnings}? The problem is that this method is
   * typically useful for {@code return} statements. That leaves the code with two options: Either
   * add the suppression to the whole method (which turns off checking for a large section of code),
   * or extract a variable, and put the suppression on that. However, a local variable typically