throws Throwable
  public static Value str_split(String string,                                @Optional("1") int chunk)    throws Throwable  {    ArrayValue array = new ArrayValueImpl();    int strLen = string.length();    for (int i = 0; i < strLen; i += chunk) {      Value value;      if (i + chunk <= strLen) {        value = new StringValueImpl(string.substring(i, i + chunk));      } else {        value = new StringValueImpl(string.substring(i));      }      array.put(new LongValue(i), value);    }    return array;  }