class_docstr: Test the FciL2NCSegmentFileHandler reader.
class_docstr_tok: ["Test","the","FciL2NCSegmentFileHandler","reader","."]
docstr: Test the correct execution of the get_dataset function with an invalid file_key.
docstr_tok: ["Test","the","correct","execution","of","the","get_dataset","function","with","an","invalid","file_key","."]
code: def test_dataset_with_invalid_filekey(self):
      """Test the correct execution of the get_dataset function with an invalid file_key."""
      self.fh = FciL2NCSegmentFileHandler(
          filename=self.seg_test_file,
          filename_info={},
          filetype_info={},
      )
  
      # Checks the correct execution of the get_dataset function with an invalid file_key
      invalid_dataset = self.fh.get_dataset(
          make_dataid(name="test_invalid", resolution=32000),
          {
              "name": "test_invalid",
              "file_key": "test_invalid",
              "fill_value": -999,
          },
      )
      # Checks that the function returns None
      assert invalid_dataset is None
  
imports: import os
  import unittest
  import uuid
  from contextlib import suppress
  from unittest import mock
  import numpy
  import pytest
  from netCDF4 import Dataset
  from pyresample import geometry
  from satpy.readers.fci_l2_nc import FciL2NCAMVFileHandler, FciL2NCFileHandler, FciL2NCSegmentFileHandler
  from satpy.tests.utils import make_dataid
label_desc: Use image node_id 5 for calling the TestFciL2NCSegmentFileHandler obj's underlying member method code with example usage: obj.test_dataset_with_invalid_filekey() without return types