关系图中，当鼠标悬停在关系边上时，能否让边两端的节点突出显示

[Lily-Jian]

One-line summary [问题简述]

在关系图中，当鼠标悬停在关系边上时，能否让边两端的节点突出显示
http://gallery.echartsjs.com/editor.html?c=xHk28KqP5-&comment=0

Version & Environment [版本及环境]

• ECharts version [ECharts 版本]: 最新版
• Browser version [浏览器类型和版本]:chrome
• OS Version [操作系统类型和版本]: win7

Expected behaviour [期望结果]

当鼠标悬停在关系边上时，能突出显示边两端的节点

ECharts option [ECharts配置项]

option = {

}

Other comments [其他信息]

[VitoWong]

Emphasis the adjacent nodes while hovering on the edge is a great feature, but show the edge label make it a really mess now, how could I only close the annoying edgeLabel? If can't, could we add a switch to this? Just NOT show the edge labels but keep the nodes, thanks!
Before:

After:(notice the black text is the mess edge labels)