def retrieve(id)
      each do |item|
        return item if item.id.eql?(id)
      end

      add_instance(member_class.retrieve(id))
    end
def retrieve(id)
      each do |item|
        return item if item.id.eql?(id)
      end

      add_instance(member_class.retrieve(id))
    end
Retrieve a collection member by its id

 @example usage
   person.question_sets.retrieve('55ef5b4e3532630003000178')
           => instance of QuestionSet

 @param id [String] resource id

 @return instance of {member_class} if found
 @raise [BlockScore::NotFoundError] otherwise

 @api public