code: def test_pep8_lines_between_cells_bis():
      prev_lines = """def f(x):
      return x""".splitlines()
  
      next_lines = """# A markdown cell
  
  # An instruction
  a = 5
  """.splitlines()
  
      assert cell_ends_with_function_or_class(prev_lines)
      assert cell_has_code(next_lines)
      assert (
          pep8_lines_between_cells(prev_lines, next_lines, ".py") == 2
      )
  
      next_lines = """# A markdown cell
  
  # Only markdown here
  # And here
  """.splitlines()
  
      assert cell_ends_with_function_or_class(prev_lines)
      assert not cell_has_code(next_lines)
      assert (
          pep8_lines_between_cells(prev_lines, next_lines, ".py") == 1
      )
  
file_path: jupytext/tests/unit/test_pep8.py
imports: from nbformat.v4.nbbase import new_code_cell, new_notebook
  from jupytext import read, reads, writes
  from jupytext.compare import compare
  from jupytext.pep8 import cell_ends_with_code, cell_ends_with_function_or_class, cell_has_code, next_instruction_is_function_or_class, pep8_lines_between_cells
label_desc: Use image node_id 5 for calling a global function with example usage: test_pep8_lines_between_cells_bis() without return types