* @param regex the regular expression to use for splitting the string
     * @return a stream of substrings resulting from splitting the input string, or an empty stream if the input is {@code null}
     */
    public static StreamOf<String> split(final String value, final String regex) {
        return stream(value == null ? null : value.split(regex));
    }

    /**

                        set,
                        new Function<String, Integer>() {
                          @Override
                          public Integer apply(String input) {
                            return input.length();
                          }
                        });
                  }

                  @SuppressWarnings("unchecked")
                  @Override

   * iterator that traverses the elements of each iterable in {@code inputs}. The input iterators
   * are not polled until necessary.
   *
   * <p>The returned iterable's iterator supports {@code remove()} when the corresponding input
   * iterator supports it. The methods of the returned iterable may throw {@code
   * NullPointerException} if any of the input iterators is {@code null}.
   *

   * iterator that traverses the elements of each iterable in {@code inputs}. The input iterators
   * are not polled until necessary.
   *
   * <p>The returned iterable's iterator supports {@code remove()} when the corresponding input
   * iterator supports it. The methods of the returned iterable may throw {@code
   * NullPointerException} if any of the input iterators is {@code null}.
   *

                    },
                    "ValidationError": {
                        "properties": {
                            "ctx": {"title": "Context", "type": "object"},
                            "input": {"title": "Input"},
                            "loc": {
                                "items": {
                                    "anyOf": [{"type": "string"}, {"type": "integer"}]
                                },

                            },
                            "msg": {"title": "Message", "type": "string"},
                            "type": {"title": "Error Type", "type": "string"},
                            "input": {"title": "Input"},
                            "ctx": {"title": "Context", "type": "object"},
                        },
                    },
                }
            },
        }

   *
   * @param cp the Unicode code point to escape if necessary
   * @return the replacement characters, or {@code null} if no escaping was needed
   */
  protected abstract char @Nullable [] escape(int cp);

  /**
   * Returns the escaped form of a given literal string.
   *

   * Returns an output {@code Future} to use in place of the given {@code input}. The output {@code
   * Future} need not be {@linkplain Future#isDone done}, making {@code AsyncFunction} suitable for
   * asynchronous derivations.
   *
   * <p>Throwing an exception from this method is equivalent to returning a failing {@code Future}.
   */
  ListenableFuture<O> apply(@ParametricNullness I input) throws Exception;

                            },
                            "msg": {"title": "Message", "type": "string"},
                            "type": {"title": "Error Type", "type": "string"},
                            "input": {"title": "Input"},
                            "ctx": {"title": "Context", "type": "object"},
                        },
                    },
                }
            },
        }

                    },
                    "ValidationError": {
                        "properties": {
                            "ctx": {"title": "Context", "type": "object"},
                            "input": {"title": "Input"},
                            "loc": {
                                "items": {
                                    "anyOf": [{"type": "string"}, {"type": "integer"}]
                                },