class_docstr: Test the MWSL1BFile reader.
docstr: Test drop coordinates.
docstr_tok: ["Test","drop","coordinates","."]
code: def test_drop_coords(reader):
      """Test drop coordinates."""
      coords = "dummy"
      data = xr.DataArray(
          np.ones(10),
          dims=("y"),
          coords={coords: 0},
      )
      assert coords in data.coords
      data = reader._drop_coords(data)
      assert coords not in data.coords
  
imports: import logging
  from datetime import datetime
  from unittest.mock import patch
  import numpy
  import pytest
  import xarray
  from netCDF4 import Dataset
  from satpy.readers.mws_l1b import MWSL1BFile, get_channel_index_from_name
label_desc: Use image node_id 17 for calling the TestMwsL1bNCFileHandler obj's underlying member method code with example usage: obj.test_drop_coords(reader) without return types