code: def get_acq_time_cds(start_time, nlines):
      """Get fake scanline acquisition times."""
      days_since_1958 = (start_time - datetime(1958, 1, 1)).days
      tline = np.zeros(
          nlines, dtype=[("days", ">u2"), ("milliseconds", ">u4")]
      )
      tline["days"][1:-1] = days_since_1958 * np.ones(nlines - 2)
      offset_second = (
          start_time
          - start_time.replace(
              hour=0, minute=0, second=0, microsecond=0
          )
      ).total_seconds() * 1000
      tline["milliseconds"][1:-1] = (
          np.arange(nlines - 2) + offset_second
      )
  
      return tline
  
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 9 for calling a global function with example usage: get_acq_time_cds(start_time, nlines) and returns: tline