About flow bug

[Lqs66]

There are three types of flow specification: flow source, flow destination and flow path. The parameter of the function flow_source is "flow_spec". When I pass in the flow source type parameter, an error will be reported. Similarly, when I pass in flow destination type parameters to flow_destination, an error will be reported. I think a function should be provided to distinguish the three flow specifications or do you have any good suggestions to me .