code: def test_plot_obj(self, target_type):
      self._test_plot_obj(target_type)
  
imports: import pytest
  import numpy
  from pdpbox.info_plots import TargetPlot, PredictPlot, InteractTargetPlot, InteractPredictPlot
  from pdpbox.utils import FeatureInfo, _make_list
  from conftest import DummyModel, PlotTestBase
label_desc: Use image node_id 3 for calling the TestTargetPlot obj's underlying member method code with example usage: obj.test_plot_obj(target_type) without return types