class_docstr: Test how metadata is combined.
class_docstr_tok: ["Test","how","metadata","is","combined","."]
docstr: Test combining one metadata object.
docstr_tok: ["Test","combining","one","metadata","object","."]
code: def test_combine_one_metadata_object(self):
      """Test combining one metadata object."""
      mda_objects = (
          {
              "_FillValue": np.nan,
              "valid_range": np.array([0.0, 0.00032], dtype=np.float32),
              "ancillary_variables": [
                  "cpp_status_flag",
                  "cpp_conditions",
                  "cpp_quality",
                  "cpp_reff_pal",
                  "-",
              ],
              "platform_name": "NOAA-20",
              "sensor": {"viirs"},
          },
      )
  
      expected = {
          "_FillValue": np.nan,
          "valid_range": np.array([0.0, 0.00032], dtype=np.float32),
          "ancillary_variables": [
              "cpp_status_flag",
              "cpp_conditions",
              "cpp_quality",
              "cpp_reff_pal",
              "-",
          ],
          "platform_name": "NOAA-20",
          "sensor": {"viirs"},
      }
  
      from satpy.dataset.metadata import combine_metadata
  
      result = combine_metadata(*mda_objects)
      assert np.allclose(
          result.pop("_FillValue"),
          expected.pop("_FillValue"),
          equal_nan=True,
      )
      assert np.allclose(
          result.pop("valid_range"), expected.pop("valid_range")
      )
      assert result == expected
  
imports: import unittest
  from datetime import datetime
  import numpy
  import pytest
  from satpy.dataset.dataid import DataID, DataQuery, ModifierTuple, WavelengthRange, minimal_default_keys_config
  from satpy.readers.pmw_channels_definitions import FrequencyDoubleSideBand, FrequencyQuadrupleSideBand, FrequencyRange
  from satpy.tests.utils import make_cid, make_dataid, make_dsq
label_desc: Use image node_id 15 for calling the TestCombineMetadata obj's underlying member method code with example usage: obj.test_combine_one_metadata_object() without return types