// This test checks reverse calls.-->{"jsonrpc":"2.0","id":2,"method":"test_callMeBackLater","params":["foo",[1]]}<--{"jsonrpc":"2.0","id":2,"result":null}<--{"jsonrpc":"2.0","id":1,"method":"foo","params":[1]}-->{"jsonrpc":"2.0","id":1,"result":"my result"}