original_string: public static function substr($string, $from, $length = null)
      {
          if (false === $encoding = mb_detect_encoding($string, null, true)) {
              return substr($string, $from, $length);
          }
  
          return mb_substr($string, $from, $length, $encoding);
      }
code: public static function substr($string, $from, $length = null)
      {
          if (false === $encoding = mb_detect_encoding($string, null, true)) {
              return substr($string, $from, $length);
          }
  
          return mb_substr($string, $from, $length, $encoding);
      }
code_tokens: public static function substr ( $ string , $ from , $ length = null ) { if ( false === $ encoding = mb_detect_encoding ( $ string , null , true ) ) { return substr ( $ string , $ from , $ length ) ; } return mb_substr ( $ string , $ from , $ length , $ encoding ) ; }
docstring: Returns the subset of a string, using mb_substr if it is available.
  
  @param string   $string String to subset
  @param int      $from   Start offset
  @param int|null $length Length to read
  
  @return string The string subset
docstring_tokens: Returns the subset of a string using mb_substr if it is available .