original_string: protected function escapeControlCharacters($string)
      {
          $escapedString = $this->escapeEscapeCharacter($string);
  
          // if no control characters
          if (!preg_match("/{$this->escapableControlCharactersPattern}/", $escapedString)) {
              return $escapedString;
          }
  
          return preg_replace_callback("/({$this->escapableControlCharactersPattern})/", function($matches) {
              return $this->controlCharactersEscapingReverseMap[$matches[0]];
          }, $escapedString);
      }
code: protected function escapeControlCharacters($string)
      {
          $escapedString = $this->escapeEscapeCharacter($string);
  
          // if no control characters
          if (!preg_match("/{$this->escapableControlCharactersPattern}/", $escapedString)) {
              return $escapedString;
          }
  
          return preg_replace_callback("/({$this->escapableControlCharactersPattern})/", function($matches) {
              return $this->controlCharactersEscapingReverseMap[$matches[0]];
          }, $escapedString);
      }
code_tokens: protected function escapeControlCharacters ( $ string ) { $ escapedString = $ this -> escapeEscapeCharacter ( $ string ) ; // if no control characters if ( ! preg_match ( "/{$this->escapableControlCharactersPattern}/" , $ escapedString ) ) { return $ escapedString ; } return preg_replace_callback ( "/({$this->escapableControlCharactersPattern})/" , function ( $ matches ) { return $ this -> controlCharactersEscapingReverseMap [ $ matches [ 0 ] ] ; } , $ escapedString ) ; }
docstring: Converts PHP control characters from the given string to OpenXML escaped control characters
  
  Excel escapes control characters with _xHHHH_ and also escapes any
  literal strings of that type by encoding the leading underscore.
  So "\0" -> _x0000_ and "_x0000_" -> _x005F_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 escape
  @return string
docstring_tokens: Converts PHP control characters from the given string to OpenXML escaped control characters