code: public List<PresentsSession> getSessionsForAddress (byte[] addr)
      {
          List<PresentsSession> sessions = Lists.newArrayListWithExpectedSize(1);
          synchronized (_usermap) {
              for (PresentsSession session : _usermap.values()) {
                  InetAddress sessionAddr = session.getInetAddress();
                  if (sessionAddr == null) {
                      continue;
                  }
                  if (Arrays.equals(addr, sessionAddr.getAddress())) {
                      sessions.add(session);
                  }
              }
          }
          return sessions;
      }
docs: Returns all sessions logged in from the given IP in the form returned from
  {@link InetAddress#getAddress()}.