code: def test_accept_empty():
      """Tests an empty dataframe is returned if you give an empty dataframe"""
      empty_frame = pd.DataFrame()
      results = lpi(empty_frame, space)
  
      assert results.columns.tolist() == ["LPI"]
      assert results.index.tolist() == list(space.keys())
      assert results["LPI"].tolist() == [0, 0]
  
      empty_frame = pd.DataFrame(columns=["x", "y", "objective"])
      results = lpi(empty_frame, space)
  
      assert results.columns.tolist() == ["LPI"]
      assert results.index.tolist() == list(space.keys())
      assert results["LPI"].tolist() == [0, 0]
  
file_path: orion/tests/unittests/analysis/test_lpi.py
imports: import copy
  import numpy
  import pandas
  from orion.analysis.base import to_numpy, train_regressor
  from orion.analysis.lpi_utils import compute_variances, lpi, make_grid
  from orion.core.io.space_builder import SpaceBuilder
label_desc: Use image node_id 1 for calling a global function with example usage: test_accept_empty() without return types