def HasAbstractFieldPath(abstract_path, store):
  """Whether a store contains abstract_path.

  Makes no provision for repeated fields. I suppose if we did we'd
  have it mean, that /any/ of the repeated subfields had such a
  subpath but, we happen to not need it.

  Args:
      abstract_path: the path to test.
      store: the store.
  Returns:
      Whether the store contains abstract_path.
  """
  tokens = abstract_path.split(".")
  for key in tokens:
    if not isinstance(store, dict) or key not in store:
      return False
    store = store.get(key, {})
  # It's ok (maybe) to even /prematurely/ reach the end of abstract_path.
  return True