class_docstr: Helper class for testing substring matching
  
  Code adapted from http://www.michaelpollmeier.com/python-mock-how-to-assert-a-substring-of-logger-output/
code: def __eq__(self, other):
      return other.lower().find(self.containing) > -1
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import random
  import tempfile
  import shutil
  import math
  import string
  import numpy
  from pandas.util.testing import assert_frame_equal
  from ..None import SArray
  import turicreate
  import sys
  from six import StringIO
  import pytest
label_desc: Use image node_id 2 for calling the SubstringMatcher obj's underlying member method code with example usage: obj.__eq__(other) and returns: unknown