Why does javadoc generate org.robolectric.shadows.__Activity__?

[utzcoz]

We can see __Activity__ when searching Activity at the search item, but when we click the link, it shows that:

http://127.0.0.1:4000/javadoc/4.4/org/robolectric/shadows/_Activity_.html

I can't find any code related to Activity in Robolectric source code, maybe it is generated by processor? cc @hoisie .