code: def test_sendfile_ssl_partial(self):
      srv_proto, cli_proto = self.prepare_sendfile(is_ssl=True)
      ret = self.run_loop(
          self.loop.sendfile(cli_proto.transport, self.file, 1000, 100)
      )
      cli_proto.transport.close()
      self.run_loop(srv_proto.done)
      self.assertEqual(ret, 100)
      self.assertEqual(srv_proto.nbytes, 100)
      self.assertEqual(srv_proto.data, self.DATA[1000:1100])
      self.assertEqual(self.file.tell(), 1100)
  
imports: import asyncio
  import errno
  import os
  import socket
  import sys
  import tempfile
  import unittest
  from asyncio import base_events
  from asyncio import constants
  from unittest import mock
  from test import support
  from test.support import os_helper
  from test.support import socket_helper
  from test.test_asyncio import utils
label_desc: Use image node_id 11 for calling the SendfileMixin obj's underlying member method code with example usage: obj.test_sendfile_ssl_partial() without return types