original_string: protected function unescapeControlCharacters($string)
      {
          $unescapedString = $string;
  
          foreach ($this->controlCharactersEscapingMap as $escapedCharValue => $charValue) {
              // only unescape characters that don't contain the escaped escape character for now
              $unescapedString = preg_replace("/(?<!_x005F)($escapedCharValue)/", $charValue, $unescapedString);
          }
  
          return $this->unescapeEscapeCharacter($unescapedString);
      }
code: protected function unescapeControlCharacters($string)
      {
          $unescapedString = $string;
  
          foreach ($this->controlCharactersEscapingMap as $escapedCharValue => $charValue) {
              // only unescape characters that don't contain the escaped escape character for now
              $unescapedString = preg_replace("/(?<!_x005F)($escapedCharValue)/", $charValue, $unescapedString);
          }
  
          return $this->unescapeEscapeCharacter($unescapedString);
      }
code_tokens: protected function unescapeControlCharacters ( $ string ) { $ unescapedString = $ string ; foreach ( $ this -> controlCharactersEscapingMap as $ escapedCharValue => $ charValue ) { // only unescape characters that don't contain the escaped escape character for now $ unescapedString = preg_replace ( "/(?<!_x005F)($escapedCharValue)/" , $ charValue , $ unescapedString ) ; } return $ this -> unescapeEscapeCharacter ( $ unescapedString ) ; }
docstring: Converts OpenXML escaped control characters from the given string to PHP control characters
  
  Excel escapes control characters with _xHHHH_ and also escapes any
  literal strings of that type by encoding the leading underscore.
  So "_x0000_" -> "\0" and "_x005F_x0000_" -> "_x0000_"
  
  NOTE: the logic has been adapted from the XlsxWriter library (BSD License)
  @link https://github.com/jmcnamara/XlsxWriter/blob/f1e610f29/xlsxwriter/sharedstrings.py#L89
  
  @param string $string String to unescape
  @return string
docstring_tokens: Converts OpenXML escaped control characters from the given string to PHP control characters