class_docstr: Customize the behavior of `generate()` and the tests that it executes.
  
  Here is sequence of steps for executing a test combination:
    1. The test combination is evaluated for whether it should be executed in
       the given environment by calling `should_execute_combination`.
    2. If the test combination is going to be executed, then the arguments for
       all combined parameters are validated.  Some arguments can be handled in
       a special way.  This is achieved by implementing that logic in
       `ParameterModifier` instances that returned from `parameter_modifiers`.
    3. Before executing the test, `context_managers` are installed
       around it.
docstr: Return context managers for running the test combination.
  
  The test combination will run under all context managers that all
  `TestCombination` instances return.
  
  Args:
    kwargs:  Arguments and their values that are passed to the test
      combination.
  
  Returns:
    A list of instantiated context managers.
docstr_tok: ["Return","context","managers","for","running","the","test","combination",".","The","test","combination","will","run","under","all","context","managers","that","all","`","TestCombination","`","instances","return",".","Args",":","kwargs",":","Arguments","and","their","values","that","are","passed","to","the","test","combination",".","Returns",":","A","list","of","instantiated","context","managers","."]
code: def context_managers(self, kwargs):
      """Return context managers for running the test combination.
  
      The test combination will run under all context managers that all
      `TestCombination` instances return.
  
      Args:
        kwargs:  Arguments and their values that are passed to the test
          combination.
  
      Returns:
        A list of instantiated context managers.
      """
      del kwargs
      return []
  
imports: from collections import OrderedDict
  import contextlib
  import types
  import unittest
  from absl.testing import parameterized
  import six
  from tensorflow.python.util import tf_inspect
label_desc: Use image node_id 3 for calling the TestCombination obj's underlying member method code with example usage: obj.context_managers(kwargs) and returns: list