code: public void addChangePlayerTypeCommand(String teamName, int unum, int playerType) {
          StringBuilder buf = new StringBuilder();
          buf.append("(change_player_type ");
          buf.append(teamName);
          buf.append(' ');
          buf.append(unum);
          buf.append(' ');
          buf.append(playerType);
          buf.append(')');
          fifo.add(fifo.size(), buf.toString());
      }
docs: Trainer only command.
  This command changes the specified players heterogeneous type.
  
  @param teamName The name of the team the player belongs to.
  @param unum The players uniform number (1~11 on pitch usually, subs <= 14).
  @param playerType A player type between 0 (the standard player) and 18. However, player.conf can change this.