code: protected function describePatternMatch($pattern, $subject)
      {
          preg_match($pattern, $subject, $matches);
          $position = strpos($subject, $matches[0]);
          $dumper   = $this->getDumper();
  
          return "Pattern [$pattern] detected at character [$position] in [" .
                  $dumper->describeValue($subject) . '] as [' .
                  $matches[0] . '] in region [' .
                  $dumper->clipString($subject, 100, $position) . ']';
      }
docs: Describes a pattern match including the string found and it's position.
  
  @param string $pattern        Regex to match against.
  @param string $subject        Subject to search.