code: def test_extract_geometry(ant, sphere, uniform, airplane, tetbeam):
      multi = multi_from_datasets(ant, sphere, uniform)
      nested = multi_from_datasets(airplane, tetbeam)
      multi.append(nested)
      # Now check everything
      assert multi.n_blocks == 4
      # Now apply the geometry filter to combine a plethora of data blocks
      geom = multi.extract_geometry()
      assert isinstance(geom, PolyData)
  
imports: import pathlib
  import platform
  import weakref
  import numpy
  import pytest
  import vtk
  import pyvista
  from pyvista import ImageData, MultiBlock, PolyData, RectilinearGrid, StructuredGrid, examples
label_desc: Use image node_id 22 for calling a global function with example usage: test_extract_geometry(ant, sphere, uniform, airplane, tetbeam) without return types