In step "Object detection imports" I am getting the following error

ImportError Traceback (most recent call last)
in ()
----> 1 from utils import label_map_util
2
3 from utils import visualization_utils as vis_util
D:\Personal\learn\ML\DL\Tensorflow\Official-Tutorial\models-master\object_detection\utils\label_map_util.py in ()
20 import tensorflow as tf
21 from google.protobuf import text_format
---> 22 from object_detection.protos import string_int_label_map_pb2
23
24
ImportError: cannot import name 'string_int_label_map_pb2'

To workaround/proceed I commented the following line in "label_map_util.py"
from object_detection.protos import string_int_label_map_pb2

But I am now getting error at step "Loading label map"
NameError: name 'string_int_label_map_pb2' is not defined

So need your help to solve the error in step "Object detection imports"
Appreciate the help to proceed further