class_docstr: Test-focused class to simplify accessing values by attribute
code: def __repr__(self):
      # use repr for values including nested cases as in tost
      ss = "\n".join(
          str(k) + " = " + repr(v).replace("\n", "\n    ")
          for k, v in vars(self).items()
      )
      ss = str(self.__class__) + "\n" + ss
      return ss
  
file_path: statsmodels/statsmodels/tools/testing.py
imports: from statsmodels.compat.pandas import testing
  import numpy.testing
  import pandas
  from statsmodels.tools.tools import Bunch
label_desc: Use image node_id 3 for calling the Holder obj's underlying member method code with example usage: obj.__repr__() and returns: ss