new_contents: import meshplex
  import numpy as np
  
  
  def test_degenerate_cell(tol=1.0e-14):
      points = [
          [0.0, 0.0],
          [0.5, 0.0],
          [1.0, 0.0],
      ]
      cells = [[0, 1, 2]]
      mesh = meshplex.Mesh(points, cells)
  
      ref = np.array([0.0])
      assert np.all(np.abs(mesh.cell_volumes - ref) < tol * (1.0 + ref))
  
      ref = np.array([[0.0], [0.0], [0.0]])
      assert np.all(np.abs(mesh.cell_volumes - ref) < tol * (1.0 + ref))
  
      # those are nan
      assert np.all(np.isnan(mesh.cell_circumradius))
      assert np.all(np.isnan(mesh.cell_circumcenters))
  
subject: add test for degenerate cells