code: public ListenableFuture<OpenedSocket> getConnection(UUID id) {
      checkState(isRunning(), "You can only get connections from a running service: %s", this);
      return getConnectionImpl(id, Source.REQUEST);
    }
docs: Returns a {@link ListenableFuture} for an open connection corresponding to the given id.
  
  <p>N.B. calling this method 'consumes' the connection and as such calling it twice with the
  same id will not work, the second future returned will never complete.  Similarly calling it
  with an id that does not correspond to a worker trying to connect will also fail.