has_many relationship in Gem


I am creating a gem in which I need to add a new has_many relationships:

...   included do |base|     base.has_many :foos   end

  def some_method     self.foos #   end ...

Here Foo is a model I created and it is places in app/models/Foo.rb

I wonder if I can use syntax like the line marked with #?

If yes, I got NoMethodError for using "self.foos" when writing rspec testing, is there any reason like forgeting to include some file of raising such an error?