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_with_HighLevelGraph(self):
      from dask.highlevelgraph import HighLevelGraph
  
      layers = {
          "a": {"x": 1, "y": (inc, "x")},
          "b": {"z": (add, (inc, "x"), "y")},
      }
      dependencies = {"a": (), "b": {"a"}}
      graph = HighLevelGraph(layers, dependencies)
      assert self.get(graph, "z") == 4
  
imports: from __future__ import annotations
  import contextlib
  import importlib
  import time
  from typing import TYPE_CHECKING
label_desc: Use image node_id 11 for calling the GetFunctionTestMixin obj's underlying member method code with example usage: obj.test_with_HighLevelGraph() without return types