How to call an msg file inside an srv file?

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In the project I am currently working on, I am trying to call the /static_map service using python file. Generally, what I am trying to do is print the map from /static_map in which /static_map is of type nav_msgs/GetMap.

GetMap.srv on the other hand consists of:

# Get the map as a nav_msgs/OccupancyGrid
---
nav_msgs/OccupancyGrid map

My question is how can I print the map from the GetMap.srv file considering that OccupancyGrid is an msg file?

This is OccupancyGrid.msg file:

# This represents a 2-D grid map, in which each cell represents the probability of
# occupancy.

Header header

#MetaData for the map
MapMetaData info

# The map data, in row-major order, starting with (0,0).  Occupancy
# probabilities are in the range [0,100].  Unknown is -1.
int8[] data

What I have implemented so far is as follow:

#! /usr/bin/env python

import rospy
from nav_msgs.srv import GetMap, GetMapResponse
from nav_msgs.msg import OccupancyGrid

def my_callback(request):

    my_response = GetMapResponse()

    return my_response

rospy.init_node('get_map_service')
map_service = rospy.Service('/static_map', GetMap, my_callback)
rospy.spin()

I have no errors whatsoever when I run this python file, but I just need it to print the map.