@RestrictedApi(explanation = "Should only be called in tests", link = "",
      allowedOnPath = ".*/src/test/.*")
  public List<BlockingServiceAndInterface> getServices() {
    return services;
  }
Returns the remote side ip address when invoked inside an RPC Returns null incase of an error.
hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/RpcServer.java