class_docstr: Tests for getting the dataset.
class_docstr_tok: ["Tests","for","getting","the","dataset","."]
code: def _fake_header():
      header = {
          "15_DATA_HEADER": {
              "SatelliteStatus": {
                  "SatelliteDefinition": {"NominalLongitude": 0.0},
                  "Orbit": {"OrbitPolynomial": ORBIT_POLYNOMIALS},
              },
              "ImageAcquisition": {
                  "PlannedAcquisitionTime": {
                      "TrueRepeatCycleStart": datetime(
                          2006, 1, 1, 12, 15, 0, 0
                      ),
                      "PlannedRepeatCycleEnd": datetime(
                          2006, 1, 1, 12, 30, 0, 0
                      ),
                  }
              },
          },
      }
      header["15_DATA_HEADER"].update(TEST_HEADER_CALIB)
      return header
  
imports: from __future__ import annotations
  import os
  import unittest
  import warnings
  from datetime import datetime
  from unittest import mock
  import dask.array
  import numpy
  import pytest
  import xarray
  from satpy.readers.eum_base import recarray2dict, time_cds_short
  from satpy.readers.seviri_l1b_native import ASCII_STARTSWITH, ImageBoundaries, NativeMSGFileHandler, Padder, get_available_channels, has_archive_header
  from satpy.tests.reader_tests.test_seviri_base import ORBIT_POLYNOMIALS, 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 2 for calling the TestNativeMSGDataset obj's underlying member method code with example usage: obj._fake_header() and returns: header