}
else if(playerRole==PlayerRole.Detective && game.getDetectives().size()>=GameEngine.MIXIMUM_NUMBER_OF_DETECTIVES){
throw new GameException("Sorry, this game is full. try to create another game and play with someone else");
}
final Player player;
if(playerRole==PlayerRole.MrX){
player = new MrX(user);
game.setMrX(player);
}else{ // if(playerRole==PlayerRole.Detective){
player = new Detective(user);
game.addDetective((Detective)player);
}
game.setPlayerPosition(player.getEmail(), game.getEmptyPositionLabel());
return ( JsonFactory.toJson( user.getName() ) );
}