code: def boundaries(self, boundaryEdges=True, featureAngle=65, nonManifoldEdges=True):
          
          fe = vtk.vtkFeatureEdges()
          fe.SetInputData(self.polydata())
          fe.SetBoundaryEdges(boundaryEdges)
          
          if featureAngle:
              fe.FeatureEdgesOn()
              fe.SetFeatureAngle(featureAngle)
          else:
              fe.FeatureEdgesOff()
          
          fe.SetNonManifoldEdges(nonManifoldEdges)
          fe.ColoringOff()
          fe.Update()
          return Actor(fe.GetOutput(), c="p").lw(5)
docs: Return an ``Actor`` that shows the boundary lines of an input mesh.
          
          :param bool boundaryEdges: Turn on/off the extraction of boundary edges.
          :param float featureAngle: Specify the feature angle for extracting feature edges.
          :param bool nonManifoldEdges: Turn on/off the extraction of non-manifold edges.