code: def test_filter(self):
      dict1 = NestedDict(
          [
              (("foo", "a"), 10),
              (("foo", "b"), 11),
              (("bar", "c"), 11),
              (("bar", "a"), 110),
          ]
      )
      dict2 = NestedDict([("foo", NestedDict(dict(a=33)))])
      dict3 = NestedDict(
          [
              ("foo", NestedDict(dict(a=None))),
              ("bar", NestedDict(dict(d=None))),
          ]
      )
      dict4 = NestedDict(
          [
              ("foo", NestedDict(dict(a=None))),
              ("bar", NestedDict(dict(c=None))),
          ]
      )
  
      self.assertEqual(dict1.filter(dict2).asdict(), {"foo": {"a": 10}})
      self.assertEqual(
          dict1.filter(dict4).asdict(),
          {"bar": {"c": 11}, "foo": {"a": 10}},
      )
      self.assertRaises(KeyError, lambda: dict1.filter(dict3).asdict())
      self.assertEqual(
          dict1.filter(dict3, ignore_missing=True).asdict(),
          {"foo": {"a": 10}},
      )
  
file_path: ray/rllib/utils/tests/test_nested_dict.py
imports: import unittest
  from ray.rllib.utils.test_utils import check
  from ray.rllib.utils.nested_dict import NestedDict
label_desc: Use image node_id 2 for calling the TestNestedDict obj's underlying member method code with example usage: obj.test_filter() without return types