docs: static boolean isRightHanded( Node seed , int idxRow , int idxCol ) {
  		Node r = seed.edges[idxRow];
  		Node c = seed.edges[idxCol];
  
  		double dirRow = Math.atan2(r.y-seed.y,r.x-seed.x);
  		double dirCol = Math.atan2(c.y-seed.y,c.x-seed.x);
  
  		return UtilAngle.distanceCW(dirRow,dirCol) < Math.PI;
  	}