code: def test_meshdata():
      """Test meshdata Class
      It's a unit square cut in two triangular element
      """
      square_vertices = np.array(
          [[0, 0, 0], [1, 0, 0], [1, 1, 0], [0, 1, 0]], dtype=np.float64
      )
      square_faces = np.array([[0, 1, 2], [0, 2, 3]], dtype=np.uint8)
      square_normals = np.array(
          [[0, 0, 1], [0, 0, 1], [0, 0, 1], [0, 0, 1]], dtype=np.float64
      )
      square_edges = np.array(
          [[0, 1], [0, 2], [0, 3], [1, 2], [2, 3]], dtype=np.uint8
      )
  
      mesh = MeshData(vertices=square_vertices, faces=square_faces)
      # test vertices and faces assignement
      assert_array_equal(square_vertices, mesh.get_vertices())
      assert_array_equal(square_faces, mesh.get_faces())
      # test normals calculus
      assert_array_equal(square_normals, mesh.get_vertex_normals())
      # test edge calculus
      assert_array_equal(square_edges, mesh.get_edges())
  
file_path: vispy/vispy/geometry/tests/test_meshdata.py
imports: import numpy
  from numpy.testing import assert_array_equal
  from vispy.testing import run_tests_if_main
  from vispy.geometry.meshdata import MeshData
label_desc: Use image node_id 1 for calling a global function with example usage: test_meshdata() without return types