throw new UnsupportedOperationException();
    }

    @Override
    public boolean putAll(@ParametricNullness K key, Iterable<? extends V> values) {
      throw new UnsupportedOperationException();
    }

    @Override
    public boolean putAll(Multimap<? extends K, ? extends V> multimap) {
      throw new UnsupportedOperationException();
    }

    @Override

      throw new UnsupportedOperationException();
    }

    @Override
    public boolean putAll(@ParametricNullness K key, Iterable<? extends V> values) {
      throw new UnsupportedOperationException();
    }

    @Override
    public boolean putAll(Multimap<? extends K, ? extends V> multimap) {
      throw new UnsupportedOperationException();
    }

    @Override

     *
     * @throws UnsupportedOperationException always
     * @deprecated Unsupported operation.
     */
    @CanIgnoreReturnValue
    @Deprecated
    @Override
    @DoNotCall("Always throws UnsupportedOperationException")
    public final boolean add(@ParametricNullness E e) {
      throw new UnsupportedOperationException();
    }

    /**

        public GeoInfo getGeoInfo() {
            throw new UnsupportedOperationException();
        }

        @Override
        public FacetInfo getFacetInfo() {
            throw new UnsupportedOperationException();
        }

        @Override
        public String getSort() {
            throw new UnsupportedOperationException();
        }

        @Override

    assertThrows(NoSuchElementException.class, () -> iterator.previous());
    assertThrows(UnsupportedOperationException.class, () -> iterator.remove());
    assertThrows(UnsupportedOperationException.class, () -> iterator.set("a"));
    assertThrows(UnsupportedOperationException.class, () -> iterator.add("a"));
  }

  public void testEmptyModifiableIterator() {

    assertThrows(NoSuchElementException.class, () -> iterator.previous());
    assertThrows(UnsupportedOperationException.class, () -> iterator.remove());
    assertThrows(UnsupportedOperationException.class, () -> iterator.set("a"));
    assertThrows(UnsupportedOperationException.class, () -> iterator.add("a"));
  }

  public void testEmptyModifiableIterator() {

    @Override
    public void remove() {
      checkRemove(false);
    }
  }

  /**
   * Returns the empty {@code Iterator} that throws {@link IllegalStateException} instead of {@link
   * UnsupportedOperationException} on a call to {@link Iterator#remove()}.
   */
  // Casting to any type is safe since there are no actual elements.
  @SuppressWarnings("unchecked")

 *
 * <p>Not every type of precondition failure is supported by these methods. Continue to throw
 * standard JDK exceptions such as {@link java.util.NoSuchElementException} or {@link
 * UnsupportedOperationException} in the situations they are intended for.
 *
 * <h3>Non-preconditions</h3>
 *
 * <p>It is of course possible to use the methods of this class to check for invalid conditions