### One-line summary `TypeError: Cannot read property getWidth of null↵ at ZRender.getWidth `
### Version & Environment [版本及环境] + ECharts version 4.1.0: + Browser version Chrome + OS Version Windows 10 ### Expected behaviour [期望结果] no exception When calling echarts.getWidth() where `echarts` is an instance returned from `onChartReady` callback. [ Full content available at: https://github.com/apache/incubator-echarts/issues/9165 ] This message was relayed via gitbox.apache.org for devnull@infra.apache.org
