lockStateChanged(this);
      }
    }
  }

  final class CycleDetectingReentrantReadWriteLock extends ReentrantReadWriteLock
      implements CycleDetectingLock {

    // These ReadLock/WriteLock implementations shadow those in the
    // ReentrantReadWriteLock superclass. They are simply wrappers around the
    // internal Sync object, so this is safe since the shadowed locks are never
    // exposed or used.

   *
   * <p>TODO: b/147144588 - We are currently also missing the methods inherited from {@link
   * AnnotatedElement}, which {@code TypeVariable} began to extend only in Java 8. Those methods
   * refer only to types present under Android, so we could implement them in {@code
   * TypeVariableImpl} today. (We could probably then make {@code TypeVariableImpl} implement {@code

   * {@code factory}, and the table contents are all serializable.
   *
   * <p>Note: the table assumes complete ownership over of {@code backingMap} and the maps returned
   * by {@code factory}. Those objects should not be manually updated and they should not use soft,
   * weak, or phantom references.
   *
   * @param backingMap place to store the mapping from each row key to its corresponding column key

   */
  // This the best we could do to get copyOfEnumSet to compile in the mainline.
  // The suppression also covers the cast to E[], discussed below.
  // In the backport, we don't have those cases and thus don't need this suppression.
  // We keep it to minimize diffs.
  @SuppressWarnings("unchecked")
  public static <E> ImmutableSet<E> copyOf(Collection<? extends E> elements) {
    /*

 * @since 20.0
 */
@J2ktIncompatible
@GwtIncompatible
public final class StatsAccumulator {
  /** Creates a new accumulator. */
  public StatsAccumulator() {}

  // These fields must satisfy the requirements of Stats' constructor as well as those of the stat
  // methods of this class.
  private long count = 0;
  private double mean = 0.0; // any finite value will do, we only use it to multiply by zero for sum

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.annotations.GwtCompatible;
import java.nio.charset.StandardCharsets;

/**
 * Static methods pertaining to ASCII characters (those in the range of values {@code 0x00} through
 * {@code 0x7F}), and to strings containing such characters.
 *
 * <p>ASCII utilities also exist in other classes of this package:
 *
 * <ul>

     *
     * <ul>
     *   <li>If {@link #MODULES} path type is also set, then the dependency can be placed either on the
     *       class path or on the module path, but only one of those. The choice is up to the plugin,
     *       possibly using heuristic rules (Maven 3 behavior).</li>
     *   <li>If a {@link #patchModule(String)} is also set and the main JAR file is placed on the module path,

 * provided {@code standardPutAll} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingNavigableMap}.
 *
 * <p>Each of the {@code standard} methods uses the map's comparator (or the natural ordering of the

 * provided {@code standardPutAll} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingNavigableMap}.
 *
 * <p>Each of the {@code standard} methods uses the map's comparator (or the natural ordering of the

  public static <R, C, V> Builder<R, C, V> builder() {
    return new Builder<>();
  }

  /**
   * Verifies that {@code rowKey}, {@code columnKey} and {@code value} are non-null, and returns a
   * new entry with those values.
   */
  static <R, C, V> Cell<R, C, V> cellOf(R rowKey, C columnKey, V value) {
    return immutableCell(
        checkNotNull(rowKey, "rowKey"),
        checkNotNull(columnKey, "columnKey"),