code: def test_grid_type(self, titanic_data, grid_type, is_valid):
      params = self.get_random_numeric_params()
      params["grid_type"] = grid_type
      self.check_valid(titanic_data, params, is_valid)
  
imports: import pandas
  import numpy
  import pytest
  from pdpbox.utils import FeatureInfo, _to_rgba, _check_col, _check_dataset, _make_list, _check_model, _check_classes, _check_memory_limit, _check_frac_to_plot, _calc_n_jobs, _get_string, _expand_params_for_interact, _calc_preds, _check_cluster_params, _check_plot_engine, _check_pdp_interact_plot_type
label_desc: Use image node_id 6 for calling the TestFeatureInfo obj's underlying member method code with example usage: obj.test_grid_type(titanic_data, grid_type, is_valid) without return types