class_docstr: A pass-through cache implementation: value generating function will be called each.
code: def get(self, key, fill_cache_func):
      return fill_cache_func()
  
imports: import abc
  import six
label_desc: Use image node_id 1 for calling the NullCache obj's underlying member method code with example usage: obj.get(key, fill_cache_func) and returns: fill_cache_func