code: def _compute_edges(self):
          
          nodes1, nodes2, nodes3 = _surface_helpers.compute_edge_nodes(
              self._nodes, self._degree
          )
          edge1 = _curve_mod.Curve(nodes1, self._degree, _copy=False)
          edge2 = _curve_mod.Curve(nodes2, self._degree, _copy=False)
          edge3 = _curve_mod.Curve(nodes3, self._degree, _copy=False)
          return edge1, edge2, edge3
docs: Compute the edges of the current surface.
  
          Returns:
              Tuple[~curve.Curve, ~curve.Curve, ~curve.Curve]: The edges of
              the surface.