Certain issues are too big to be handled in a single PR. These issues are tagged with label "epic" either by the developer or the tech lead.
Divide the original problem into multiple issues.
Each sub-issue should mentione
Ref issue ####.
In this way Github will automaticaly link a child issue
with its epic issue.
Now work on these child issue and send PR to close these child issues.
Once all the sub-issues are closed then assing the epic issue to a QA person. An issue tagged with "epic" should never be closed by a PR. It should be closed manually by a QA.