I am trying to pass a lookup into my PCF component but do not see any property for lookups in the ComponentFramework d.ts. Help would be appreciated

I am trying to pass a lookup into my PCF component but do not see any property for lookups in the ComponentFramework d.ts. Help would be appreciated
I believe it's a work in progress.
Lookups are far harder to handle than other data types especially when the aim is to provide a single component framework for both Data Driven and Canvas apps.