class_docstr: Tests for getting the dataset.
class_docstr_tok: ["Tests","for","getting","the","dataset","."]
code: def _exp_data_array():
      expected = xr.DataArray(
          np.array(
              [
                  [4.0, 32.0, 193.0, 5.0],
                  [24.0, 112.0, 514.0, 266.0],
                  [44.0, 192.0, 835.0, 527.0],
                  [64.0, 273.0, 132.0, 788.0],
              ],
              dtype=np.float32,
          ),
          dims=["y", "x"],
          attrs={
              "orbital_parameters": {
                  "satellite_actual_longitude": -3.55117540817073,
                  "satellite_actual_latitude": -0.5711243456528018,
                  "satellite_actual_altitude": 35783296.150123544,
                  "satellite_nominal_longitude": 0.0,
                  "satellite_nominal_latitude": 0.0,
                  "projection_longitude": 0.0,
                  "projection_latitude": 0.0,
                  "projection_altitude": 35785831.0,
              },
              "time_parameters": {
                  "nominal_start_time": datetime(2006, 1, 1, 12, 15, 0),
                  "nominal_end_time": datetime(2006, 1, 1, 12, 30, 0),
                  "observation_start_time": datetime(
                      2006, 1, 1, 12, 15, 9, 304888
                  ),
                  "observation_end_time": datetime(
                      2006, 1, 1, 12, 27, 9, 304888
                  ),
              },
              "georef_offset_corrected": True,
              "platform_name": "MSG-3",
              "sensor": "seviri",
              "units": "1",
              "wavelength": (1, 2, 3),
              "standard_name": "counts",
          },
      )
      expected["acq_time"] = (
          "y",
          [
              np.datetime64("1958-01-02 00:00:01").astype(
                  "datetime64[ns]"
              ),
              np.datetime64("1958-01-02 00:00:02").astype(
                  "datetime64[ns]"
              ),
              np.datetime64("1958-01-02 00:00:03").astype(
                  "datetime64[ns]"
              ),
              np.datetime64("1958-01-02 00:00:04").astype(
                  "datetime64[ns]"
              ),
          ],
      )
      return expected
  
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 7 for calling the TestNativeMSGDataset obj's underlying member method code with example usage: obj._exp_data_array() and returns: expected