Results caching with object set to false

[shmeltex]

I'm trying to figure out how to use results caching with following rabl:

object false

child :employees => :data do
    extends "employees/_single"
end

node(:success) { true }
node(:total) { employees.size }

If I just add cache then run into error ActionView::Template::Error: undefined method 'cache_key' for nil:NilClass

If add cache with a block

object false

cache { |_| "#{ employees.cache_key }" }

child :employees => :data do
  extends "employees/_single"
end

node(:success) { true }
node(:total) { employees.size }

then it can't resolve employees: ActionView::Template::Error: undefined local variable or method 'employees' for RablRails::Renderers::JSON:Module

What's the right approach here?