original_string: public function getRequirement($key)
      {
          return isset($this->requirements[$key]) ? $this->requirements[$key] : null;
      }
code: public function getRequirement($key)
      {
          return isset($this->requirements[$key]) ? $this->requirements[$key] : null;
      }
code_tokens: public function getRequirement ( $ key ) { return isset ( $ this -> requirements [ $ key ] ) ? $ this -> requirements [ $ key ] : null ; }
docstring: Returns the requirement for the given key.
  
  @param string $key The key
  
  @return string|null The regex or null when not given
docstring_tokens: Returns the requirement for the given key .