src/main/java/com/webcheckers/appl/PlayerLobby.java
public Player signIn(String username){
        if(players != null && !(isLoggedIn(username)) && (isValidUsername(username))){
            Player newPlayer = new Player(username);
            players.put(username, newPlayer);
            return  newPlayer;
        }
        else return null;
    }
/**
     * Signs into the server
     * @param username the username to sign in under
     * @return a new player representing that player
     */
Signs into the server
@param username the username to sign in under
@return a new player representing that player
Signs into the server @param username the username to sign in under @return a new player representing that player
public Player signIn(String username){
        if(players != null && !(isLoggedIn(username)) && (isValidUsername(username))){
            Player newPlayer = new Player(username);
            players.put(username, newPlayer);
            return  newPlayer;
        }
        else return null;
    }
public Player signIn ( String username ) { if ( players != null && ! ( isLoggedIn ( username ) ) && ( isValidUsername ( username ) ) ) { Player newPlayer = new Player ( username ) ; players . put ( username , newPlayer ) ; return newPlayer ; } else return null ; }
Signs into the server
 @param username the username to sign in under
 @return a new player representing that player
Signs into the server @param username the username to sign in under @return a new player representing that player