class_docstr: Test the scene class.
class_docstr_tok: ["Test","the","scene","class","."]
docstr: Test initializing with a single string as filenames.
docstr_tok: ["Test","initializing","with","a","single","string","as","filenames","."]
code: def test_init_str_filename(self):
      """Test initializing with a single string as filenames."""
      with pytest.raises(
          ValueError, match="'filenames' must be a list of files: .*"
      ):
          Scene(reader="blo", filenames="test.nc")
  
imports: import os
  import random
  import string
  from copy import deepcopy
  from unittest import mock
  import pytest
  import satpy
  from satpy import Scene
  from satpy.tests.utils import FAKE_FILEHANDLER_END, FAKE_FILEHANDLER_START, spy_decorator
label_desc: Use image node_id 2 for calling the TestScene obj's underlying member method code with example usage: obj.test_init_str_filename() without return types