code: def Polygon(center=(0.,0.,0.), radius=1, normal=(0,0,1), n_sides=6):
      
      src = vtk.vtkRegularPolygonSource()
      src.SetCenter(center)
      src.SetNumberOfSides(n_sides)
      src.SetRadius(radius)
      src.SetNormal(normal)
      src.Update()
      return vtki.wrap(src.GetOutput())
docs: Createa a polygonal disk with a hole in the center. The disk has zero
      height. The user can specify the inner and outer radius of the disk, and
      the radial and circumferential resolution of the polygonal representation.
  
      Parameters
      ----------
      center : np.ndarray or list
          Center in [x, y, z]. middle of the axis of the polygon.
  
      radius : float
          The radius of the polygon
  
      normal : np.ndarray or list
          direction vector in [x, y, z]. orientation vector of the cone.
  
      n_sides : int
          Number of sides of the polygon