* Returns the value associated with {@code key} in this cache, first loading that value if
   * necessary. No observable state associated with this cache is modified until loading completes.
   *
   * <p>If another call to {@link #get} or {@link #getUnchecked} is currently loading the value for
   * {@code key}, simply waits for that thread to finish and returns its loaded value. Note that
   * multiple threads can concurrently load values for distinct keys.
   *

   *
   * <ul>
   *   <li>Its execution does not cause any observable side effects.
   *   <li>The computation is <i>consistent with equals</i>; that is, {@link Objects#equal
   *       Objects.equal}{@code (a, b)} implies that {@code Objects.equal(function.apply(a),
   *       function.apply(b))}.
   * </ul>
   *
   * @throws NullPointerException if {@code input} is null and this function does not accept null

import javax.annotation.CheckForNull;

/**
 * An {@link OutputStream} that starts buffering to a byte array, but switches to file buffering
 * once the data reaches a configurable size.
 *
 * <p>When this stream creates a temporary file, it restricts the file's permissions to the current
 * user or, in the case of Android, the current app. If that is not possible (as is the case under

 * {@code CharSink} is not an open, stateful stream that can be written to and closed. Instead, it
 * is an immutable <i>supplier</i> of {@code Writer} instances.
 *
 * <p>{@code CharSink} provides two kinds of methods:
 *
 * <ul>
 *   <li><b>Methods that return a writer:</b> These methods should return a <i>new</i>, independent
 *       instance each time they are called. The caller is responsible for ensuring that the
 *       returned writer is closed.

   * Returns the value associated with {@code key} in this cache, first loading that value if
   * necessary. No observable state associated with this cache is modified until loading completes.
   *
   * <p>If another call to {@link #get} or {@link #getUnchecked} is currently loading the value for
   * {@code key}, simply waits for that thread to finish and returns its loaded value. Note that
   * multiple threads can concurrently load values for distinct keys.
   *

   *
   * <p>Implementations of {@code AbstractIterator} that wish to expose this functionality should
   * implement {@code PeekingIterator}.
   */
  @ParametricNullness
  public final T peek() {
    if (!hasNext()) {
      throw new NoSuchElementException();
    }
    // Safe because hasNext() ensures that tryToComputeNext() has put a T into `next`.
    return uncheckedCastNullableTToT(next);
  }

      }
    }
  }

  /** Tests that if specify '%' as safe the result is an idempotent escaper. */
  public void testCustomEscaper_withpercent() {
    UnicodeEscaper e = new PercentEscaper("%", false);
    assertEquals("foo%7Cbar", e.escape("foo|bar"));
    assertEquals("foo%7Cbar", e.escape("foo%7Cbar")); // idempotent
  }

  /** Test that giving a null 'safeChars' string causes a {@link NullPointerException}. */

 * UnicodeEscaper}. They are heavily optimized for performance and greatly simplify the task of
 * implementing new escapers. It is strongly recommended that when implementing a new escaper you
 * extend one of these classes. If you find that you are unable to achieve the desired behavior
 * using either of these classes, please contact the Java libraries team for advice.
 *

import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import junit.framework.TestCase;

/**
 * Unit tests for any listenable future that chains other listenable futures. Unit tests need only
 * override buildChainingFuture and getSuccessfulResult, but they can add custom tests as needed.
 *
 * @author Nishant Thakkar
 */

import java.util.concurrent.Executor;

/**
 * An {@link EventBus} that takes the Executor of your choice and uses it to dispatch events,
 * allowing dispatch to occur asynchronously.
 *
 * @author Cliff Biffle
 * @since 10.0
 */
@ElementTypesAreNonnullByDefault
public class AsyncEventBus extends EventBus {

  /**
   * Creates a new AsyncEventBus that will use {@code executor} to dispatch events. Assigns {@code