code: def cell_nodes_x(self):
          
          decoder = self.decoder
          xcoord = self.xcoord
          data = self.data
          xbounds = decoder.get_cell_node_coord(
              data, coords=data.coords, axis='x')
          if self.plotter.convert_radian:
              xbounds = convert_radian(xbounds, xcoord, xbounds)
          return xbounds.values
docs: The unstructured x-boundaries with shape (N, m) where m > 2