code: private function moveStringCursor($positionOffset, $byteStreamOffset)
      {
          $this->position           += $positionOffset;
          $this->byteStreamPosition += $byteStreamOffset;
  
          return $this;
      }
docs: Moves internal string cursor position
  
  @param int $positionOffset
  @param int $byteStreamOffset
  
  @return self