I print the parameter graph_json in
void GraphExecutor::Init(const std::string& graph_json, tvm::runtime::Module module, const std::vector& devs, const PackedFunc lookup_linked_param_func) {
the graph includes operators like
{ "op": "null", "name": "p0", "inputs": [] }, { "op": "null", "name": "p1", "inputs": [] },
What does this type of op means? I don’t unstand the function of that