Add test demonstrating issue
Add test demonstrating issue

Expanded columns don't handle None values correctly.
The query the column builds uses "=" when it should
use "is".

qedsoftware/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq