this(new TreeMap<K, V>(map));
  }

  private SafeTreeMap(NavigableMap<K, V> delegate) {
    this.delegate = delegate;
    if (delegate == null) {
      throw new NullPointerException();
    }
    for (K k : keySet()) {
      checkValid(k);
    }
  }

  @Override
  public @Nullable Entry<K, V> ceilingEntry(K key) {
    return delegate.ceilingEntry(checkValid(key));
  }

    expectContents(expected);
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_KEYS)
  public void testPut_nullKeyUnsupported() {
    assertThrows(NullPointerException.class, () -> put(nullKeyEntry));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported put(null, value)");
  }

          .put(IndexOutOfBoundsException.class, e -> e instanceof IndexOutOfBoundsException)
          .put(NoSuchElementException.class, e -> e instanceof NoSuchElementException)
          .put(NullPointerException.class, e -> e instanceof NullPointerException)
          .put(NumberFormatException.class, e -> e instanceof NumberFormatException)
          .put(RuntimeException.class, e -> e instanceof RuntimeException)

   * throws a {@code ClassCastException} or {@code NullPointerException}.
   */
  static boolean safeContains(Collection<?> collection, @CheckForNull Object object) {
    checkNotNull(collection);
    try {
      return collection.contains(object);
    } catch (ClassCastException | NullPointerException e) {
      return false;
    }
  }

  /**

  protected CharEscaper() {}

  /**
   * Returns the escaped form of a given literal string.
   *
   * @param string the literal string to be escaped
   * @return the escaped form of {@code string}
   * @throws NullPointerException if {@code string} is null
   */
  @Override
  public String escape(String string) {
    checkNotNull(string); // GWT specific check (do not optimize)

        ImmutableList.copyOf(returnType.getActualTypeArguments()));
  }

  public void testConstructor_exceptionTypes() throws Exception {
    assertEquals(
        ImmutableList.of(TypeToken.of(NullPointerException.class)),
        Prepender.constructor(String.class, int.class).getExceptionTypes());
  }

  public void testConstructor_typeParameters() throws Exception {

        ImmutableList.copyOf(returnType.getActualTypeArguments()));
  }

  public void testConstructor_exceptionTypes() throws Exception {
    assertEquals(
        ImmutableList.of(TypeToken.of(NullPointerException.class)),
        Prepender.constructor(String.class, int.class).getExceptionTypes());
  }

  public void testConstructor_typeParameters() throws Exception {

    List<Object> list = new ArrayList<>(equalityGroup.length);
    for (int i = 0; i < equalityGroup.length; i++) {
      Object element = equalityGroup[i];
      if (element == null) {
        throw new NullPointerException("at index " + i);
      }
      list.add(element);
    }
    equalityGroups.add(list);
    return this;
  }

  /** Run tests on equals method, throwing a failure on an invalid test */

  public void testRemove_nullNotSupported() {
    try {
      assertFalse(
          "remove(null) should return false or throw NullPointerException",
          collection.remove(null));
    } catch (NullPointerException tolerated) {
    }
    expectUnchanged();
  }

  @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_QUERIES})
  public void testRemove_nullAllowed() {

    expectContents(createArrayWithNullKey());
  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullKeyUnsupported() {
    assertThrows(NullPointerException.class, () -> initMapWithNullKey());
  }

  @MapFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullValueSupported() {
    initMapWithNullValue();