code: def _iter_keys(self, prefix):
      assert prefix == NAMESPACE_PREFIX
      for k in self._mock_resources.keys():
          yield k, k.removeprefix(prefix)
  
imports: import stat
  import unittest
  import yaml
  from collections import namedtuple
  from unittest.mock import patch
  from parameterized import parameterized
  import __res
label_desc: Use image node_id 3 for calling the ImporterMocks obj's underlying member method code with example usage: obj._iter_keys(prefix) without return types