code: def test_get_lightly_server_location_from_env(self):
      os.environ[
          "LIGHTLY_SERVER_LOCATION"
      ] = "https://api.dev.lightly.ai/ "
      host = get_lightly_server_location_from_env()
      self.assertEqual(host, "https://api.dev.lightly.ai")
  
file_path: lightly/tests/api/test_utils.py
imports: import os
  import unittest
  from unittest import mock
  import pytest
  from PIL import Image
  from lightly.api.utils import DatasourceType, PIL_to_bytes, get_lightly_server_location_from_env, get_signed_url_destination, getenv, paginate_endpoint, retry
label_desc: Use image node_id 7 for calling the TestUtils obj's underlying member method code with example usage: obj.test_get_lightly_server_location_from_env() without return types