function line(p1, p2) {
        if (!(this instanceof line))
            return new line(p1, p2);
            this.start = point(p1);
        this.end = point(p2);
    }
function line(p1, p2) {
        if (!(this instanceof line))
            return new line(p1, p2);
            this.start = point(p1);
        this.end = point(p2);
    }
function line ( p1 , p2 ) { if ( ! ( this instanceof line ) ) return new line ( p1 , p2 ) ; this . start = point ( p1 ) ; this . end = point ( p2 ) ; }
Line. -----
Line . -----