Approval Flow - Approval Status - why can't this be updated?

Any help would be appreciated folks. All examples of flow approvals i have found relate to Lists, not Documents. @DeanGross, thanks for reminding me of the edX resource, i had forgotten about that. However the example you have given is a list and as far as i can tell your Status field is a hand crafted field with options?!?. I am referring to a document library with Approval turned on, which obviously then automatically produces the [Approval Status] field. This [Approval Status] field is the one i cannot change in a flow, and as far as others have posted, as of yet you cannot update the [Approval Status] with a flow. Hope someone can point me in the right directions.