      } else {
              return '???';
            }
          },
          mapMouseDown(e) {
            e = e || window.event;
            e.preventDefault();
            this.dragX = e.clientX;
            this.dragY = e.clientY;
            document.onmouseup = () => {
              document.onmouseup = null;
              document.onmousemove = null;
            };
            document.onmousemove = (e) => {
              e = e || window.event;
              e.preventDefault();
              this.c