CAP entity modelling and HANA IDENTITY columns

I am looking at converting our existing HANA entities defined with hdbcds files into the CAP model.

CAP provides the common UUID type but I am having the requirement to define a key field using the HANA IDENTITY type.

So eg the following field:

key ID: Integer64 generated always as identity(start with 1 increment by 1);

I don't seem to be able to find the same functionality within CDS.

How can we achieve the above ?

Basically I want to be sure I have an incremental value whenever a new entry is created. I could redefine the on create event and perform a select I guess but what with concurrency, etc ..