original_string: protected function keyForRange($key, \DateTime $start, \DateTime $end)
      {
          return 'range:' . $key . '_' . $this->dateString($start) . '_' . $this->dateString($end);
      }
code: protected function keyForRange($key, \DateTime $start, \DateTime $end)
      {
          return 'range:' . $key . '_' . $this->dateString($start) . '_' . $this->dateString($end);
      }
code_tokens: protected function keyForRange ( $ key , \ DateTime $ start , \ DateTime $ end ) { return 'range:' . $ key . '_' . $ this -> dateString ( $ start ) . '_' . $ this -> dateString ( $ end ) ; }
docstring: Generate key for key and date range.
  
  @param string $key Counter key.
  @param \DateTime $start Start date.
  @param \DateTime $end End date.
  @return string
docstring_tokens: Generate key for key and date range .