code: def get_acq_time_exp(start_time, nlines):
      """Get expected scanline acquisition times."""
      tline_exp = np.zeros(464, dtype="datetime64[ms]")
      tline_exp[0] = np.datetime64("NaT")
      tline_exp[-1] = np.datetime64("NaT")
      tline_exp[1:-1] = np.datetime64(start_time)
      tline_exp[1:-1] += np.arange(nlines - 2).astype("timedelta64[ms]")
  
      return tline_exp.astype("datetime64[ns]")
  
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 10 for calling a global function with example usage: get_acq_time_exp(start_time, nlines) and returns: tline_exp