code: def get_fake_filename_info(start_time):
      """Create fake filename information."""
      return {
          "platform_shortname": "MSG3",
          "start_time": start_time,
          "service": "MSG",
      }
  
file_path: satpy/satpy/tests/reader_tests/test_seviri_l1b_hrit_setup.py
imports: from datetime import datetime
  from unittest import mock
  import numpy
  from satpy.readers.seviri_l1b_hrit import HRITMSGFileHandler, HRITMSGPrologueFileHandler
  from satpy.tests.reader_tests.test_seviri_base import ORBIT_POLYNOMIALS
label_desc: Use image node_id 7 for calling a global function with example usage: get_fake_filename_info(start_time) and returns: dict