class_docstr: Test VIIRS SDR Reader.
class_docstr_tok: ["Test","VIIRS","SDR","Reader","."]
code: def _assert_reflectance_properties(
      self, data_arr, num_scans=16, with_area=True
  ):
      assert np.issubdtype(data_arr.dtype, np.float32)
      assert data_arr.attrs["calibration"] == "reflectance"
      assert data_arr.attrs["units"] == "%"
      assert data_arr.attrs["rows_per_scan"] == num_scans
      if with_area:
          assert "area" in data_arr.attrs
          assert data_arr.attrs["area"] is not None
          assert data_arr.attrs["area"].shape == data_arr.shape
      else:
          assert "area" not in data_arr.attrs
  
imports: import os
  import unittest
  from contextlib import contextmanager
  from unittest import mock
  import numpy
  import pytest
  from satpy.readers.viirs_atms_sdr_base import DATASET_KEYS
  from satpy.tests.reader_tests.test_hdf5_utils import FakeHDF5FileHandler
label_desc: Use image node_id 1 for calling the TestVIIRSSDRReader obj's underlying member method code with example usage: obj._assert_reflectance_properties(data_arr, num_scans, with_area) without return types