original_string: protected function replaceConfigExpression($matches) {
  		$property = $matches[1];
  		//check key existence
  		if (!array_key_exists($property, $this->config))
  			return '';
  		//convert to string, if possible
  		if (($str = $this->toString($this->config[$property])) === false)
  			return '';
  		return $str;
  	}
code: protected function replaceConfigExpression($matches) {
  		$property = $matches[1];
  		//check key existence
  		if (!array_key_exists($property, $this->config))
  			return '';
  		//convert to string, if possible
  		if (($str = $this->toString($this->config[$property])) === false)
  			return '';
  		return $str;
  	}
code_tokens: protected function replaceConfigExpression ( $ matches ) { $ property = $ matches [ 1 ] ; //check key existence if ( ! array_key_exists ( $ property , $ this -> config ) ) return '' ; //convert to string, if possible if ( ( $ str = $ this -> toString ( $ this -> config [ $ property ] ) ) === false ) return '' ; return $ str ; }
docstring: Returns a string that replaces a configuration expression within a string
  @param array $matches
  @return string
docstring_tokens: Returns a string that replaces a configuration expression within a string