The discv5 implementation only allows a single concurrent request to another peer. However, there seems no inherent reason as each request contains a random request ID that allows matching the responses with the requests.
This PR also adds back the discv5/discv4 test cases.
The discv5 implementation only allows a single concurrent request to another peer. However, there seems no inherent reason as each request contains a random request ID that allows matching the responses with the requests.
This PR also adds back the discv5/discv4 test cases.