code: private function ensureAreSeparate(DocBlock $doc, Annotation $first, Annotation $second)
      {
          $pos = $first->getEnd();
          $final = $second->getStart() - 1;
  
          // check if we need to add a line, or need to remove one or more lines
          if ($pos === $final) {
              $doc->getLine($pos)->addBlank();
  
              return;
          }
  
          for ($pos = $pos + 1; $pos < $final; ++$pos) {
              $doc->getLine($pos)->remove();
          }
      }
docs: Force the given annotations to have one empty line between each other.
  
  @param DocBlock   $doc
  @param Annotation $first
  @param Annotation $second