Wicegrid nested model

I am using wicegrid 3.0.4 in Rails 3 application. I have nested models. I am not sure how to use it with wicegrid.

Example:

Class A
  has_many :B
end

Class B
  belongs_to :A
  has_many :C
end

Class C
  belongs_to :B
end

In Controller:

initialize_grid(A, :include => [:B]) 

How can we get class C's data? Any suggestions?

Thanks, Avinash