class ActiveModel::Serializer

def associations
  associations = self.class._associations
  included_associations = filter(associations.keys)
  associations.each_with_object({}) do |(name, association), hash|
    if included_associations.include? name
      if association.embed_ids?
        hash[association.key] = serialize_ids association
      elsif association.embed_objects?
        hash[association.embedded_key] = serialize association
      end
    end
  end
end