Push modes

PushType is being set when specifying the Push action. It drives what is meant to happen depending on whether a Revit element correspondent to the pushed BHoM object already exists in the model. The way in which the Revit elements get linked to BHoM objects is explained in BHoM vs Revit identity section.

Currently following PushTypes are provided by the Adapter, with following actions being taken for each:

PushType	Revit element exists	Revit element does not exist
CreateOnly	do nothing	create new element
UpdateOnly	update existing element	do nothing
DeleteThenCreate	delete existing element and create new one	create new element
CreateNonExisting	not implemented	not implemented
FullPush	not implemented	not implemented

Default PushType for Revit Adapter is PushType.DeleteThenCreate.