title: ECharts - How to prevent changing background color on hover
body: <p>I would like to prevent background-color from changing when I hover on ECharts map.
  For example, see this link <a href="https://echarts.apache.org/examples/en/editor.html?c=map-usa" rel="nofollow noreferrer">https://echarts.apache.org/examples/en/editor.html?c=map-usa</a>.  How can I hover over the map but the colors of the map remain unchanged.  I do not want the background color changing (to yellow in this case) when I hover my mouse on any part of the map</p>