new_contents: from pytest import mark
  from procs.api import spawn
  
  
  @mark.parametrize('cmd', (
      'echo hello',
      [['echo', 'hello']],
      ['echo hello'],
  ))
  def test_spawn_parses_all_argtypes(cmd):
      assert spawn(cmd).stdout == 'hello\n'
  
subject: test high level API