code: def test_xdmf_reader():
      filename = examples.download_meshio_xdmf(load=False)
  
      reader = pv.get_reader(filename)
      assert isinstance(reader, pv.XdmfReader)
      assert reader.path == filename
  
      assert reader.number_time_points == 5
      assert reader.time_values == [0.0, 0.25, 0.5, 0.75, 1.0]
      assert reader.time_point_value(0) == 0.0
      assert reader.time_point_value(1) == 0.25
  
      assert reader.number_grids == 6
      assert reader.number_point_arrays == 2
  
      assert reader.point_array_names == ["phi", "u"]
      assert reader.cell_array_names == ["a"]
  
      blocks = reader.read()
      assert reader.active_time_value == 0.0
      assert np.array_equal(
          blocks["TimeSeries_meshio"]["phi"],
          np.array([0.0, 0.0, 0.0, 0.0]),
      )
      reader.set_active_time_value(0.25)
      assert reader.active_time_value == 0.25
      blocks = reader.read()
      assert np.array_equal(
          blocks["TimeSeries_meshio"]["phi"],
          np.array([0.25, 0.25, 0.25, 0.25]),
      )
      reader.set_active_time_value(0.5)
      assert reader.active_time_value == 0.5
      blocks = reader.read()
      assert np.array_equal(
          blocks["TimeSeries_meshio"]["phi"],
          np.array([0.5, 0.5, 0.5, 0.5]),
      )
      reader.set_active_time_value(0.75)
      assert reader.active_time_value == 0.75
      blocks = reader.read()
      assert np.array_equal(
          blocks["TimeSeries_meshio"]["phi"],
          np.array([0.75, 0.75, 0.75, 0.75]),
      )
      reader.set_active_time_value(1.0)
      assert reader.active_time_value == 1.0
      blocks = reader.read()
      assert np.array_equal(
          blocks["TimeSeries_meshio"]["phi"],
          np.array([1.0, 1.0, 1.0, 1.0]),
      )
  
      reader.set_active_time_point(0)
      assert reader.active_time_value == 0.0
  
      with pytest.raises(ValueError, match="Not a valid time"):
          reader.set_active_time_value(1000.0)
  
imports: import os
  import platform
  import numpy
  import pytest
  import pyvista
  from pyvista import examples
  from pyvista.core.utilities.fileio import _try_imageio_imread
  from pyvista.examples.downloads import download_file
label_desc: Use image node_id 50 for calling a global function with example usage: test_xdmf_reader() without return types