class_docstr: Test various meris_nc_sen3 filehandlers.
class_docstr_tok: ["Test","various","meris_nc_sen3","filehandlers","."]
docstr: Test initialization of file handlers.
docstr_tok: ["Test","initialization","of","file","handlers","."]
code: def test_instantiate(self, mocked_dataset):
      """Test initialization of file handlers."""
      from satpy.readers.meris_nc_sen3 import (
          NCMERIS2,
          NCMERISCal,
          NCMERISGeo,
      )
      from satpy.tests.utils import make_dataid
  
      ds_id = make_dataid(name="M01", calibration="reflectance")
      ds_id2 = make_dataid(name="wsqf", calibration="reflectance")
      filename_info = {
          "mission_id": "ENV",
          "dataset_name": "M01",
          "start_time": 0,
          "end_time": 0,
      }
  
      test = NCMERISCal("somedir/somefile.nc", filename_info, "c")
      test.get_dataset(ds_id, filename_info)
      mocked_dataset.assert_called()
      mocked_dataset.reset_mock()
  
      test = NCMERISGeo("somedir/somefile.nc", filename_info, "c")
      test.get_dataset(ds_id, filename_info)
      mocked_dataset.assert_called()
      mocked_dataset.reset_mock()
  
      test = NCMERIS2("somedir/somefile.nc", filename_info, "c")
      test.get_dataset(ds_id, {"nc_key": "the_key"})
      test.get_dataset(ds_id2, {"nc_key": "the_key"})
      mocked_dataset.assert_called()
      mocked_dataset.reset_mock()
  
file_path: satpy/satpy/tests/reader_tests/test_meris_nc.py
imports: import unittest
  import unittest.mock
label_desc: Use image node_id 1 for calling the TestMERISReader obj's underlying member method code with example usage: obj.test_instantiate(mocked_dataset) without return types