code: def test_convert_numpy_panel_to_series():
      """Test output format of panel-to-series for numpy type input."""
      X_panel = _make_panel(
          n_instances=1, n_columns=2, return_mtype="numpy3D"
      )
      _, n_var, n_time = X_panel.shape
  
      X_series = convert_Panel_to_Series(X_panel)
  
      assert isinstance(X_series, np.ndarray)
      assert X_series.ndim == 2
      assert X_series.shape == (n_time, n_var)
  
file_path: sktime/sktime/datatypes/tests/test_series_to_panel_converters.py
imports: import numpy
  import pandas
  from sktime.datatypes._series_as_panel import convert_Panel_to_Series, convert_Series_to_Panel
  from sktime.utils._testing.panel import _make_panel
  from sktime.utils._testing.series import _make_series
label_desc: Use image node_id 2 for calling a global function with example usage: test_convert_numpy_panel_to_series() without return types