code: @SuppressWarnings("WeakerAccess")
      public int getPlayerDBServerPort(int player) {
          ensureRunning();
          Integer result = dbServerPorts.get(player);
          if (result == null) {
              return -1;
          }
          return result;
      }
docs: Look up the database server port reported by a given player. You should not use this port directly; instead
  ask this class for a session to use while you communicate with the database.
  
  @param player the player number of interest
  
  @return the port number on which its database server is running, or -1 if unknown
  
  @throws IllegalStateException if not running