Reduce allocations in join()
Reduce allocations in join()

benchmark          old ns/op     new ns/op     delta
BenchmarkReply     9189          8984          -2.23%

benchmark          old allocs     new allocs     delta
BenchmarkReply     14             13             -7.14%

benchmark          old bytes     new bytes     delta
BenchmarkReply     1576          872           -44.67%

pteichman/fate