def create(params = {})
      fail Error, 'Create parent first' unless parent.id
      assoc_params = default_params.merge(params)

      add_instance(member_class.create(assoc_params))
    end
def create(params = {})
      fail Error, 'Create parent first' unless parent.id
      assoc_params = default_params.merge(params)

      add_instance(member_class.create(assoc_params))
    end
Initialize a collection member and save it

 @example
   >> person.question_sets.create
   => #<BlockScore::QuestionSet:0x3fc67a6007f4 JSON:{
     "object": "question_set",
     "id": "55ef5d5b62386200030001b3",
     "created_at": 1441750363,
     ...
     }

 @param params [Hash] params

 @return new saved instance of {member_class}

 @api public