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

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

     * @throws NullPointerException if {@code replacement} is null
     */
    @CanIgnoreReturnValue
    public Builder addEscape(char c, String replacement) {
      checkNotNull(replacement);
      // This can replace an existing character (the builder is re-usable).
      replacementMap.put(c, replacement);
      return this;
    }

    /** Returns a new escaper based on the current state of the builder. */
    public Escaper build() {

    for (; index < slen; index++) {

      // Get a replacement for the current character.
      char[] r = escape(s.charAt(index));

      // If no replacement is needed, just continue.
      if (r == null) {
        continue;
      }

      int rlen = r.length;
      int charsSkipped = index - lastEscape;

      // This is the size needed to add the replacement, not the full size

      ListenableFuture<? extends V> replacement = fallback.apply(cause);
      checkNotNull(
          replacement,
          "AsyncFunction.apply returned null instead of a Future. "
              + "Did you mean to return immediateFuture(null)? %s",
          fallback);
      return replacement;
    }

    @Override
    void setResult(ListenableFuture<? extends V> result) {

@ElementTypesAreNonnullByDefault
abstract class CommonMatcher {
  public abstract boolean matches();

  public abstract boolean find();

  public abstract boolean find(int index);

  public abstract String replaceAll(String replacement);

  public abstract int end();

  public abstract int start();

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Private replacement for {@link com.google.gwt.user.client.rpc.GwtTransient} to work around
 * build-system quirks. This annotation should be used <b>only</b> in {@code
 * com.google.common.collect}.
 */
@Documented
@GwtCompatible

@ElementTypesAreNonnullByDefault
class CompactLinkedHashMap<K extends @Nullable Object, V extends @Nullable Object>
    extends CompactHashMap<K, V> {
  // TODO(lowasser): implement removeEldestEntry so this can be used as a drop-in replacement

  /** Creates an empty {@code CompactLinkedHashMap} instance. */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      CompactLinkedHashMap<K, V> create() {
    return new CompactLinkedHashMap<>();

@ElementTypesAreNonnullByDefault
class CompactHashMap<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractMap<K, V> implements Serializable {
  /*
   * TODO: Make this a drop-in replacement for j.u. versions, actually drop them in, and test the
   * world. Figure out what sort of space-time tradeoff we're actually going to get here with the

    Comparator<? super K> keyComparator = (Comparator<? super K>) Comparable::compareTo;
    sort(insertionOrder, Helpers.entryComparator(keyComparator));
    return insertionOrder;
  }

  /**
   * Private replacement for {@link com.google.gwt.user.client.rpc.GwtTransient} to work around
   * build-system quirks.
   */
  private @interface GwtTransient {}

  /**