code: def decast(origin_model, oplist):
      
      graph = origin_model.graph
      nodelist = list(graph.node)
      del graph.node[:]
  
      all_nodes = LinkedNode.build_from_onnx(nodelist,
                                             [],
                                             [i_.name for i_ in graph.input],
                                             [o_.name for o_ in graph.output])
  
      nodes = remove_cast(all_nodes, set(oplist))
      for n_ in nodes:
          graph.node.extend(n_.generate())
  
      return origin_model
docs: remove the ONNX cast op from the specified operator.
      :param origin_model:these
      :param oplist:
      :return: