class_docstr: A ref could not be resolved.
class_docstr_tok: ["A","ref","could","not","be","resolved","."]
code: def __str__(self):
      return str(self._cause)
  
imports: from collections import defaultdict, deque
  import itertools
  import pprint
  import textwrap
  import attr
  from jsonschema import _utils
  from jsonschema.compat import PY3, iteritems
label_desc: Use image node_id 1 for calling the RefResolutionError obj's underlying member method code with example usage: obj.__str__() and returns: str