* this structure is never mutated, it provides a thread-safe view of the backing map.
 *
 * <p>The {@link MapIteratorCache} assumes ownership of the backing map, and cannot guarantee
 * correctness in the face of external mutations to the backing map. As such, it is <b>strongly</b>
 * recommended that the caller does not persist a reference to the backing map (unless the backing
 * map is immutable).
 *

 * <p>{@code Graph}s built by this class also guarantee that each collection-returning accessor
 * returns a <b>(live) unmodifiable view</b>; see <a
 * href="https://github.com/google/guava/wiki/GraphsExplained#accessor-behavior">the external
 * documentation</a> for details.
 *
 * <p>Examples of use:
 *
 * <pre>{@code
 * // Building a mutable graph
 * MutableGraph<String> graph = GraphBuilder.undirected().allowsSelfLoops(true).build();

  private XmlEscapers() {}

  private static final char MIN_ASCII_CONTROL_CHAR = 0x00;
  private static final char MAX_ASCII_CONTROL_CHAR = 0x1F;

  // For each xxxEscaper() method, please add links to external reference pages
  // that are considered authoritative for the behavior of that escaper.

  /**
   * Returns an {@link Escaper} instance that escapes special characters in a string so it can

 * <p>{@code Graph}s built by this class also guarantee that each collection-returning accessor
 * returns a <b>(live) unmodifiable view</b>; see <a
 * href="https://github.com/google/guava/wiki/GraphsExplained#accessor-behavior">the external
 * documentation</a> for details.
 *
 * <p>Examples of use:
 *
 * <pre>{@code
 * // Building a mutable graph
 * MutableGraph<String> graph = GraphBuilder.undirected().allowsSelfLoops(true).build();

   * grab a lock.
   */
  // @Immutable except that Throwable is mutable (initCause(), setStackTrace(), mutable subclasses).
  private static final class StateSnapshot {
    /**
     * The internal state, which equals external state unless shutdownWhenStartupFinishes is true.
     */
    final State state;

    /** If true, the user requested a shutdown while the service was still starting up. */

 * <p>{@code Network}s built by this class also guarantee that each collection-returning accessor
 * returns a <b>(live) unmodifiable view</b>; see <a
 * href="https://github.com/google/guava/wiki/GraphsExplained#accessor-behavior">the external
 * documentation</a> for details.
 *
 * <p>Examples of use:
 *
 * <pre>{@code
 * // Building a mutable network
 * MutableNetwork<String, Integer> network =

 * returns a <b>(live) unmodifiable view</b>; see <a
 * href="https://github.com/google/guava/wiki/GraphsExplained#accessor-behavior">the external
 * documentation</a> for details.
 *
 * <p>Examples of use:
 *
 * <pre>{@code
 * // Building a mutable value graph
 * MutableValueGraph<String, Double> graph =

   * grab a lock.
   */
  // @Immutable except that Throwable is mutable (initCause(), setStackTrace(), mutable subclasses).
  private static final class StateSnapshot {
    /**
     * The internal state, which equals external state unless shutdownWhenStartupFinishes is true.
     */
    final State state;

    /** If true, the user requested a shutdown while the service was still starting up. */

 * returns a <b>(live) unmodifiable view</b>; see <a
 * href="https://github.com/google/guava/wiki/GraphsExplained#accessor-behavior">the external
 * documentation</a> for details.
 *
 * <p>Examples of use:
 *
 * <pre>{@code
 * // Building a mutable value graph
 * MutableValueGraph<String, Double> graph =

  public final <T extends @Nullable Object> T[] toArray(T[] other) {
    checkNotNull(other);
    int size = size();

    if (other.length < size) {
      Object[] internal = internalArray();
      if (internal != null) {
        return Platform.copy(internal, internalArrayStart(), internalArrayEnd(), other);
      }
      other = ObjectArrays.newArray(other, size);
    } else if (other.length > size) {
      other[size] = null;