class_docstr: Tests for the cuDFInterface.
class_docstr_tok: ["Tests","for","the","cuDFInterface","."]
code: def test_dataset_mixed_type_range(self):
      ds = Dataset((["A", "B", "C", None],), "A")
      vmin, vmax = ds.range(0)
      self.assertTrue(np.isnan(vmin))
      self.assertTrue(np.isnan(vmax))
  
imports: import logging
  from unittest import SkipTest
  import numpy
  from holoviews.core.data import Dataset
  from holoviews.core.spaces import HoloMap
  from .base import HeterogeneousColumnTests, InterfaceTests
label_desc: Use image node_id 3 for calling the cuDFInterfaceTests obj's underlying member method code with example usage: obj.test_dataset_mixed_type_range() without return types