code: def test_check_format_no_name():
      """[Utils] _check_format: test non-named instance does not pass."""
  
      instances = [("ols-1", OLS()), OLS()]
      assert not _check_format(instances)
  
file_path: mlens/mlens/utils/tests/test_formatting.py
imports: from mlens.utils.dummy import OLS
  from mlens.utils.formatting import _check_format, _assert_format, _format_instances, _check_instances
label_desc: Use image node_id 3 for calling a global function with example usage: test_check_format_no_name() without return types