code: def test_multiline_metadata(
      no_jupytext_version_number,
      notebook=new_notebook(
          metadata={
              "multiline": """A multiline string
  
  with a blank line""",
              "jupytext": {"notebook_metadata_filter": "all"},
          }
      ),
      markdown="""---
  jupyter:
    jupytext:
      notebook_metadata_filter: all
    multiline: 'A multiline string
  
  
      with a blank line'
  ---
  """,
  ):
      actual = jupytext.writes(notebook, ".md")
      compare(actual, markdown)
      nb2 = jupytext.reads(markdown, ".md")
      compare(nb2, notebook)
  
file_path: jupytext/tests/unit/test_header.py
imports: from nbformat.v4.nbbase import new_markdown_cell, new_notebook, new_raw_cell
  import jupytext
  from jupytext.compare import compare
  from jupytext.formats import get_format_implementation
  from jupytext.header import header_to_metadata_and_cell, metadata_and_cell_to_header, uncomment_line
label_desc: Use image node_id 8 for calling a global function with example usage: test_multiline_metadata(no_jupytext_version_number, notebook, markdown) without return types