class_docstr: Test the HRITFileHandler.
class_docstr_tok: ["Test","the","HRITFileHandler","."]
docstr: Set up the hrit file handler for testing HRV.
docstr_tok: ["Set","up","the","hrit","file","handler","for","testing","HRV","."]
code: def setUp(self):
      """Set up the hrit file handler for testing HRV."""
      self.observation_start_time = datetime(
          2006, 1, 1, 12, 15, 9, 304888
      )
      self.nlines = 464
      self.reader = setup.get_fake_file_handler(
          observation_start_time=self.observation_start_time,
          nlines=self.nlines,
          ncols=5568,
      )
      self.reader.mda.update(
          {
              "segment_sequence_number": 18,
              "planned_start_segment_number": 1,
          }
      )
      self.reader.fill_hrv = True
  
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 1 for calling the TestHRITMSGFileHandlerHRV obj's underlying member method code with example usage: obj.setUp() without return types