code: def test_read_cgns():
      filename = examples.download_cgns_structured(load=False)
      reader = pv.get_reader(filename)
      assert isinstance(reader, pv.CGNSReader)
      assert "CGNS" in str(reader)
      reader.show_progress()
      assert reader._progress_bar is True
  
      assert reader.distribute_blocks in [
          True,
          False,
      ]  # don't insist on a VTK default
      reader.distribute_blocks = True
      assert reader.distribute_blocks
      reader.disable_all_bases()
      reader.disable_all_families()
      reader.disable_all_cell_arrays()
      reader.disable_all_point_arrays()
      reader.load_boundary_patch = False
      empty_block = reader.read()
      assert len(empty_block) == 0
  
      reader.enable_all_bases()
      reader.enable_all_families()
      reader.enable_all_cell_arrays()
      reader.enable_all_point_arrays()
  
      # check can modify unsteady_pattern
      orig = reader.unsteady_pattern
      reader.unsteady_pattern = not orig
      assert reader.unsteady_pattern is not orig
  
      # check can modify vector_3d
      orig = reader.vector_3d
      reader.vector_3d = not orig
      assert reader.vector_3d is not orig
  
      # check can boundary_patch accessible
      assert reader.load_boundary_patch in [True, False]
  
      reader.hide_progress()
      assert reader._progress_bar is False
  
      block = reader.read()
      assert len(block[0]) == 12
  
      # actual block
      assert len(block[0][0].cell_data) == 3
  
      assert reader.base_array_names == ["SQNZ"]
      assert reader.base_array_status("SQNZ") is True
  
      assert reader.family_array_names == [
          "inflow",
          "outflow",
          "sym",
          "wall",
      ]
      assert reader.family_array_status("inflow") is True
  
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 36 for calling a global function with example usage: test_read_cgns() without return types