code: def test_negative_cell_metadata_filter():
      assert filter_metadata(
          to_dict(["exectime"]), "-linesto", "-exectime"
      ) == to_dict([])
  
imports: from copy import deepcopy
  import pytest
  from nbformat.v4.nbbase import new_code_cell, new_notebook
  from jupytext import reads, writes
  from jupytext.cli import jupytext
  from jupytext.compare import compare, compare_notebooks
  from jupytext.metadata_filter import filter_metadata, metadata_filter_as_dict
label_desc: Use image node_id 7 for calling a global function with example usage: test_negative_cell_metadata_filter() without return types