class ActiveFedora::Associations::CollectionProxy

def include?(record)

person.pets.include?(Pet.find(21)) # => false
person.pets.include?(Pet.find(20)) # => true

person.pets # => [#]

end
has_many :pets
class Person < ActiveFedora::Base

Returns +true+ if the given object is present in the collection.
def include?(record)
  @association.include?(record)
end