remove unused functions in default_runner

Summary: No usage: https://www.internalfb.com/code/search?q=filepath%3Ad2go%2F%20repo%3Afbcode%20_mock_func

Differential Revision: D31591868

fbshipit-source-id: 3fc6103c40713fa7bf278fd57a3e8fb4436a0902

d2go/runner/default_runner.py

@@ -2,7 +2,6 @@
 # Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
 
 
-import contextlib
 import logging
 import math
 import os
@@ -12,7 +11,6 @@ from typing import Type, Optional, List
 
 import d2go.utils.abnormal_checker as abnormal_checker
 import detectron2.utils.comm as comm
-import mock
 import torch
 from d2go.config import (
     CfgNode,
@@ -74,16 +72,6 @@ from mobile_cv.predictor.api import PredictorWrapper
 logger = logging.getLogger(__name__)
 
 
-@contextlib.contextmanager
-def _mock_func(module, src_func, target_func):
-    with mock.patch(
-        "{}.{}".format(module.__name__, src_func.__name__), side_effect=target_func
-    ) as mocked_func:
-        yield
-    if not mocked_func.call_count >= 1:
-        logger.warning("Didn't patch the {} in module {}".format(src_func, module))
-
-
 ALL_TB_WRITERS = []