* Futures#addCallback addCallback()}.
   *
   * <p>Memory consistency effects: Actions in a thread prior to adding a listener <a
   * href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-17.html#jls-17.4.5">
   * <i>happen-before</i></a> its execution begins, perhaps in another thread.
   *
   * <p>Guava implementations of {@code ListenableFuture} promptly release references to listeners

 *
 * @author Ben Yu
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
public final class Defaults {
  private Defaults() {}

  private static final Double DOUBLE_DEFAULT = 0d;
  private static final Float FLOAT_DEFAULT = 0f;

  /**
   * Returns the default value of {@code type} as defined by JLS --- {@code 0} for numbers, {@code

 *
 * @author Ben Yu
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
public final class Defaults {
  private Defaults() {}

  private static final Double DOUBLE_DEFAULT = 0d;
  private static final Float FLOAT_DEFAULT = 0f;

  /**
   * Returns the default value of {@code type} as defined by JLS --- {@code 0} for numbers, {@code

   * Futures#addCallback addCallback()}.
   *
   * <p>Memory consistency effects: Actions in a thread prior to adding a listener <a
   * href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-17.html#jls-17.4.5">
   * <i>happen-before</i></a> its execution begins, perhaps in another thread.
   *
   * <p>Guava implementations of {@code ListenableFuture} promptly release references to listeners

   * Futures#addCallback addCallback()}.
   *
   * <p>Memory consistency effects: Actions in a thread prior to adding a listener <a
   * href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-17.html#jls-17.4.5">
   * <i>happen-before</i></a> its execution begins, perhaps in another thread.
   *
   * <p>Guava implementations of {@code ListenableFuture} promptly release references to listeners

              <placement>X</placement>
            </tag>
            <tag>
              <name>implSpec</name>
              <placement>X</placement>
            </tag>
            <tag>
              <name>jls</name>
              <placement>X</placement>
            </tag>
            <tag>
              <name>revised</name>
              <placement>X</placement>
            </tag>
            <tag>

    }

    return classes;
  }

  /**
   * Not really a signature -- just the parts that affect whether one method is a fauxveride of a
   * method from an ancestor class.
   *
   * <p>See JLS 8.4.2 for the definition of the related "override-equivalent."
   */
  private static final class MethodSignature implements Comparable<MethodSignature> {
    final String name;
    final List<Class<?>> parameterTypes;