code: def test_read_magics(text="// :vars\n"):
      nb = jupytext.reads(text, "rs")
      compare_notebooks(
          nb, new_notebook(cells=[new_code_cell(":vars")])
      )
      compare(jupytext.writes(nb, "rs"), text)
  
imports: from nbformat.v4.nbbase import new_code_cell, new_markdown_cell, new_notebook
  import jupytext
  from jupytext.compare import compare, compare_notebooks
label_desc: Use image node_id 1 for calling a global function with example usage: test_read_magics(text) without return types