class_docstr: The GetFunctionTestCase class can be imported and used to test foreign
  implementations of the `get` function specification. It aims to enforce all
  known expectations of `get` functions.
  
  To use the class, inherit from it and override the `get` function. For
  example:
  
  > from dask.utils_test import GetFunctionTestMixin
  > class TestCustomGet(GetFunctionTestMixin):
       get = staticmethod(myget)
  
  Note that the foreign `myget` function has to be explicitly decorated as a
  staticmethod.
code: def test_data_not_in_dict_is_ok(self):
      d = {"x": 1, "y": (add, "x", 10)}
      assert self.get(d, "y") == 11
  
imports: from __future__ import annotations
  import contextlib
  import importlib
  import time
  from typing import TYPE_CHECKING
label_desc: Use image node_id 4 for calling the GetFunctionTestMixin obj's underlying member method code with example usage: obj.test_data_not_in_dict_is_ok() without return types