Accessing the context from the promises?

[zedtux]

I'd like to ensure my Interator fills in an Array with a size based on an attribute from the context:

promises do
  required(:users).filled(min_size?: context.user_ids.size)
end

But that's not possible since the context is now accessible:

NameError (undefined local variable or method `context' for #<Dry::Schema::DSL:0x0000557f84f3c6a0>):

Would it make sens to add it or am I trying to use this gem in a wrong way?