code: def print_pack(document_loader,  # type: Loader
                 processobj,       # type: CommentedMap
                 uri,              # type: Text
                 metadata          # type: Dict[Text, Any]
                ):  # type (...) -> Text
      
      packed = pack(document_loader, processobj, uri, metadata)
      if len(packed["$graph"]) > 1:
          return json_dumps(packed, indent=4)
      return json_dumps(packed["$graph"][0], indent=4)
docs: Return a CWL serialization of the CWL document in JSON.