docs: private final void _writeString(char[] text, int offset, int len)
          throws IOException, JsonGenerationException
      {
          if (_maximumNonEscapedChar != 0) {
              _writeStringASCII(text, offset, len, _maximumNonEscapedChar);
              return;
          }
          
          /* Let's just find longest spans of non-escapable
           * content, and for each see if it makes sense
           * to copy them, or write through
           */
          len += offset; // -> len marks the end from now on
          final int[] escCodes = _outputEscapes;
          final int escLen = escCodes.length;
          while (offset < len) {
              int start = offset;
  
              while (true) {
                  char c = text[offset];
                  if (c < escLen && escCodes[c] != 0) {
                      break;
                  }
                  if (++offset >= len) {
                      break;
                  }
              }
  
              // Short span? Better just copy it to buffer first:
              int newAmount = offset - start;
              if (newAmount < SHORT_WRITE) {
                  // Note: let's reserve room for escaped char (up to 6 chars)
                  if ((_outputTail + newAmount) > _outputEnd) {
                      _flushBuffer();
                  }
                  if (newAmount > 0) {
                      System.arraycopy(text, start, _outputBuffer, _outputTail, newAmount);
                      _outputTail += newAmount;
                  }
              } else { // Nope: better just write through
                  _flushBuffer();
                  _writer.write(text, start, newAmount);
              }
              // Was this the end?
              if (offset >= len) { // yup
                  break;
              }
              // Nope, need to escape the char.
              char c = text[offset++];
              _appendCharacterEscape(c, escCodes[c]);          
          }
      }