}
        };
    EscaperAsserts.assertBasic(surrogateEscaper);

    // A surrogate pair defining a code point within the safe range.
    String safeInput = "\uD800\uDC00"; // 0x10000
    assertEquals(safeInput, surrogateEscaper.escape(safeInput));

    // A surrogate pair defining a code point outside the safe range (but both
    // of the surrogate characters lie within the safe range). It is important

          // Mostly 3-byte UTF-8 sequences - "Asian" text
          return Character.MIN_SUPPLEMENTARY_CODE_POINT;
        } else if (userFriendly.matches("(?i)(?:Cuneiform|rare|exotic|supplementary.*)")) {
          // Mostly 4-byte UTF-8 sequences - "rare exotic" text
          return Character.MAX_CODE_POINT;
        } else {
          throw new IllegalArgumentException("Can't decode codepoint " + userFriendly);
        }
      }

      @Override
      @CheckForNull
      protected char[] escape(int cp) {
        // If a code point maps to a single character, just escape that.
        if (cp < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
          return escaper.escape((char) cp);
        }
        // Convert the code point to a surrogate pair and escape them both.
        // Note: This code path is horribly slow and typically allocates 4 new

     *
     * 1) To invoke FinalizableReference.finalizeReferent()
     *
     * 2) To detect when FinalizableReference's class loader has to be garbage collected, at which
     * point, Finalizer can stop running
     */
    if (!finalizableReferenceClass.getName().equals(FINALIZABLE_REFERENCE)) {
      throw new IllegalArgumentException("Expected " + FINALIZABLE_REFERENCE + ".");
    }

  }

  private boolean allBmp(String string) {
    // Ordinarily we'd use something like i += Character.charCount(string.codePointAt(i)) here. But
    // we can get away with i++ because the whole point of this method is to return false if we find
    // a code point that doesn't fit in a char.
    for (int i = 0; i < string.length(); i++) {
      if (string.codePointAt(i) > 0xffff) {
        return false;
      }
    }
    return true;
  }

   *
   * Now, Finalizer no longer keeps an indirect strong reference to the static
   * FinalizableReferenceQueue field in ReferenceMap. The application class loader can be reclaimed
   * at which point the Finalizer thread will stop and its decoupled class loader can also be
   * reclaimed.
   *
   * If any of this fails along the way, we fall back to loading Finalizer directly in the
   * application class loader.
   *

   *
   * Now, Finalizer no longer keeps an indirect strong reference to the static
   * FinalizableReferenceQueue field in ReferenceMap. The application class loader can be reclaimed
   * at which point the Finalizer thread will stop and its decoupled class loader can also be
   * reclaimed.
   *
   * If any of this fails along the way, we fall back to loading Finalizer directly in the
   * application class loader.
   *

  private final char[][] replacements;
  // The number of elements in the replacement array.
  private final int replacementsLength;
  // The first code point in the safe range.
  private final int safeMin;
  // The last code point in the safe range.
  private final int safeMax;

  // Cropped values used in the fast path range checks.
  private final char safeMinChar;
  private final char safeMaxChar;

    /**
     * The elements of a {@link ConcurrentlyMutatedList} are added and removed over time. This
     * method returns every state that the list has passed through at some point.
     */
    Set<List<E>> getAllStates();
  }

  /**
   * Returns a {@link ConcurrentlyMutatedList} that performs the given operations as its concurrent

    // let the computation proceed
    computingLatch.countDown();
    // don't check cache.size() until we know the get("b") call is complete
    computationComplete.await();

    // At this point, the listener should be holding the seed value (a -> a), and the map should
    // contain the computed value (b -> b), since the clear() happened before the computation
    // completed.
    assertEquals(1, listener.size());