code: def test_param_from_and_to_line(
      line_in: str, line_out: Optional[str]
  ):
      param = Param.from_line(line_in)
      assert param is not None
      assert param.to_line() == line_out
  
file_path: allennlp/scripts/tests/py2md/py2md_test.py
imports: from typing import Optional
  import pytest
  from allennlp.common.testing import AllenNlpTestCase
  from scripts.py2md import py2md, Param, DocstringError
label_desc: Use image node_id 1 for calling a global function with example usage: test_param_from_and_to_line(line_in, line_out) without return types