class_docstr: Make blob objects behave like Python strings.
  
  Expects that classes that use this mixin to have a _strkey() method that
  returns the string to apply string methods to. Using _strkey() instead
  of __str__ ensures consistent behavior between Python 2 and 3.
docstr: Implements the `in` keyword like a Python string.
docstr_tok: ["Implements","the","`","in","`","keyword","like","a","Python","string","."]
code: def __contains__(self, sub):
      """Implements the `in` keyword like a Python string."""
      return sub in self._strkey()
  
imports: from __future__ import absolute_import
  import sys
  from textblob.compat import basestring, implements_to_string, PY2, binary_type
label_desc: Use image node_id 5 for calling the StringlikeMixin obj's underlying member method code with example usage: obj.__contains__(sub) and returns: unknown