isWhiteOrBlackRectangle(p1, p2, p3, p4) {
			let corr = 3;
			p1 = new Point(p1.getX() - corr, p1.getY() + corr);
			p2 = new Point(p2.getX() - corr, p2.getY() - corr);
			p3 = new Point(p3.getX() + corr, p3.getY() - corr);
			p4 = new Point(p4.getX() + corr, p4.getY() + corr);
			let cInit = this.getColor(p4, p1);
			if (cInit === 0) {
				return false;
			}
			let c = this.getColor(p1, p2);
			if (c !== cInit) {
				return false;
			}
			c = this.getColor(p2, p3);
			if (c !== cInit) {
				return false;
			}
			c = this.getColor(p3, p4);
			return c === cInit;
		}
@return true if the border of the rectangle passed in parameter is compound of white points only
        or black points only