docs: public SocketAndStreams checkout(SocketDestination destination) {
          try {
              // time checkout
              long start = System.nanoTime();
              SocketAndStreams sas = pool.checkout(destination);
              updateStats(System.nanoTime() - start);
  
              return sas;
          } catch(Exception e) {
              throw UnreachableStoreException.wrap("Failure while checking out socket for "
                                                  + destination + ": ", e);
          }
      }