detectSolid2(points) {
			// A..D
			// :  :
			// B--C
			let pointA = points[0];
			let pointB = points[1];
			let pointC = points[2];
			let pointD = points[3];
			// Transition detection on the edge is not stable.
			// To safely detect, shift the points to the module center.
			let tr = this.transitionsBetween(pointA, pointD);
			let pointBs = Detector$1.shiftPoint(pointB, pointC, (tr + 1) * 4);
			let pointCs = Detector$1.shiftPoint(pointC, pointB, (tr + 1) * 4);
			let trBA = this.transitionsBetween(pointBs, pointA);
			let trCD = this.transitionsBetween(pointCs, pointD);
			// 0..3
			// |  :
			// 1--2
			if (trBA < trCD) {
				// solid sides: A-B-C
				points[0] = pointA;
				points[1] = pointB;
				points[2] = pointC;
				points[3] = pointD;
			}
			else {
				// solid sides: B-C-D
				points[0] = pointB;
				points[1] = pointC;
				points[2] = pointD;
				points[3] = pointA;
			}
			return points;
		}
Detect a second solid side next to first solid side.