changeRowSize(size) {
        if (size == undefined || size < 1 || size > 10) return;
        if (this.rows == size) return;
        var obj = new TTY(this.x, this.y, this.scope, size, this.cols);
        this.delete();
        simulationArea.lastSelected = obj;
        return obj;
    }
@memberof TTY
this function is used to change the size of the screen