code: function(node1, node2){
  		var bx1=node1.obj.bx, by1=node1.obj.by, bx2=node2.obj.bx, by2=node2.obj.by;
  		if(bx1>bx2||((bx1===bx2)&&(by1>by2))){ return null;}
  		return this.board.getobj(((bx1+bx2)>>1), ((by1+by2)>>1));
  	}
docs: --------------------------------------------------------------------------- component.getLinkObjByNodes()  node間のオブジェクトを取得する ---------------------------------------------------------------------------