code: def check_common(self, plot_obj, model_type):
      assert plot_obj.plot_type == "pdp_interact"
      n_grids = []
      for obj in plot_obj.pdp_isolate_objs:
          assert isinstance(obj, PDPIsolate)
          assert isinstance(obj.feature_info, FeatureInfo)
          n_grids.append(obj.n_grids)
  
      target_len = (
          plot_obj.n_classes if model_type == "multi-class" else 1
      )
      assert plot_obj.target == list(range(target_len))
      assert len(plot_obj.results) == target_len
      assert plot_obj.n_grids == np.prod(n_grids)
      assert len(plot_obj.feature_grid_combos) == plot_obj.n_grids
  
      for cls_idx, res in enumerate(plot_obj.results):
          assert isinstance(res, PDPResult)
          assert (
              res.class_id == cls_idx
              if model_type == "multi-class"
              else res.class_id is None
          )
          assert res.ice_lines.shape == (
              self.data_gen.DUMMY_DF_LENGTH,
              plot_obj.n_grids,
          )
          assert res.pdp.shape == (plot_obj.n_grids,)
  
imports: import numpy
  import pytest
  import copy
  from abc import abstractmethod
  from pdpbox.pdp import PDPResult, PDPIsolate, PDPInteract
  from pdpbox.utils import FeatureInfo, _make_list
  from conftest import DummyModel, PlotTestBase
label_desc: Use image node_id 2 for calling the TestPDPInteract obj's underlying member method code with example usage: obj.check_common(plot_obj, model_type) without return types