original_string: protected function _processString($str, $opts)
      {
          if (!empty($opts['length'])) {
              return substr($str, empty($opts['start']) ? 0 : $opts['start'], $opts['length']);
          } elseif (!empty($opts['start'])) {
              return substr($str, $opts['start']);
          }
  
          return $str;
      }
code: protected function _processString($str, $opts)
      {
          if (!empty($opts['length'])) {
              return substr($str, empty($opts['start']) ? 0 : $opts['start'], $opts['length']);
          } elseif (!empty($opts['start'])) {
              return substr($str, $opts['start']);
          }
  
          return $str;
      }
code_tokens: protected function _processString ( $ str , $ opts ) { if ( ! empty ( $ opts [ 'length' ] ) ) { return substr ( $ str , empty ( $ opts [ 'start' ] ) ? 0 : $ opts [ 'start' ] , $ opts [ 'length' ] ) ; } elseif ( ! empty ( $ opts [ 'start' ] ) ) { return substr ( $ str , $ opts [ 'start' ] ) ; } return $ str ; }
docstring: Process a string response based on criteria options.
  
  @param string $str  The original string.
  @param array $opts  The criteria options.
  
  @return string  The requested string.
docstring_tokens: Process a string response based on criteria options .