About the parameter delay

In my python, it seems that the delay wouldn't work. No matter what kinds of number I type in, it just wouldn't work. And the pic it generates is damaged. I can't open it.  But the html file is ok. Weird.

[Covid-19(1).zip](https://github.com/pyecharts/pyecharts-snapshot/files/4696496/Covid-19.1.zip)

