class_docstr: Unit tests for SEVIRI netCDF reader.
class_docstr_tok: ["Unit","tests","for","SEVIRI","netCDF","reader","."]
docstr: Test start/end nominal/observation time handling.
docstr_tok: ["Test","start\/end","nominal\/observation","time","handling","."]
code: def test_time(self, file_handler):
      """Test start/end nominal/observation time handling."""
      assert (
          datetime(2020, 1, 1, 0, 0)
          == file_handler.observation_start_time
      )
      assert datetime(2020, 1, 1, 0, 0) == file_handler.start_time
      assert file_handler.start_time == file_handler.nominal_start_time
  
      assert (
          datetime(2020, 1, 1, 0, 0)
          == file_handler.observation_end_time
      )
      assert file_handler.end_time == file_handler.nominal_end_time
      assert datetime(2020, 1, 1, 0, 0) == file_handler.end_time
  
imports: from datetime import datetime
  from unittest import mock
  import numpy
  import pytest
  import xarray
  from satpy.readers.seviri_l1b_nc import NCSEVIRIFileHandler
  from satpy.tests.reader_tests.test_seviri_base import ORBIT_POLYNOMIALS
  from satpy.tests.reader_tests.test_seviri_l1b_calibration import TestFileHandlerCalibrationBase
  from satpy.tests.utils import assert_attrs_equal, make_dataid
label_desc: Use image node_id 7 for calling the TestNCSEVIRIFileHandler obj's underlying member method code with example usage: obj.test_time(file_handler) without return types