class_docstr: Test the HRITFileHandler.
class_docstr_tok: ["Test","the","HRITFileHandler","."]
docstr: Test getting the area def.
docstr_tok: ["Test","getting","the","area","def","."]
code: def test_get_area_def(self):
      """Test getting the area def."""
      area = self.reader.get_area_def(
          make_dataid(name="VIS006", resolution=3000)
      )
  
      expected_crs = CRS(
          dict(
              a=6378169.0,
              b=6356583.8,
              h=35785831.0,
              lon_0=self.projection_longitude,
              proj="geos",
              units="m",
          )
      )
      assert area.crs == expected_crs
  
      assert area.area_extent == (
          -77771774058.38356,
          -3720765401003.719,
          30310525626438.438,
          77771774058.38356,
      )
  
      # Data shifted by 1.5km to N-W
      self.reader.mda["offset_corrected"] = False
      area = self.reader.get_area_def(
          make_dataid(name="VIS006", resolution=3000)
      )
      assert area.area_extent == (
          -77771772558.38356,
          -3720765402503.719,
          30310525627938.438,
          77771772558.38356,
      )
  
      assert area.area_id == "msg_seviri_rss_3km"
  
imports: import unittest
  from datetime import datetime
  from unittest import mock
  import numpy
  import pytest
  import xarray
  from numpy import testing
  from pyproj import CRS
  import satpy.tests.reader_tests.test_seviri_l1b_hrit_setup
  from satpy.readers.seviri_l1b_hrit import HRITMSGEpilogueFileHandler, HRITMSGFileHandler, HRITMSGPrologueFileHandler
  from satpy.tests.reader_tests.test_seviri_base import ORBIT_POLYNOMIALS_INVALID
  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 3 for calling the TestHRITMSGFileHandler obj's underlying member method code with example usage: obj.test_get_area_def() without return types