The context cannot be obtained after the toDataURL is called

[xiaoxiaofu1]

Describe the bug / 问题描述

export class LinearEdge extends Quadratic {
render(attributes, container) {
console.log(this.context)
super.render(attributes);
}
}
调用.toDataURL()后报错，获取不到context了，点之前都正常

Reproduction link / 重现链接

No response

Steps to Reproduce the Bug or Issue / 重现步骤

No response

G6 Version / G6 版本

🆕 5.x

Operating System / 操作系统

macOS

Browser / 浏览器

Chrome

Additional context / 补充说明

No response