public boolean equals(Object obj) {       
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof AxisSpace)) {
            return false;
        }
        AxisSpace that = (AxisSpace) obj;
        if (this.top != that.top) {
            return false;
        }   
        if (this.bottom != that.bottom) {
            return false;
        }
        if (this.left != that.left) {
            return false;
        }
        if (this.right != that.right) {
            return false;
        }
        return true;