code: public function create(Room $room, MemberCollection $members)
      {
          $result = $this->client->post('rooms', [
              'name' => $room->name,
              'description' => $room->description,
              'members_admin_ids' => implode(',', $members->getAdminIds()),
              'members_member_ids' => implode(',', $members->getMemberIds()),
              'members_readonly_ids' => implode(',', $members->getReadonlyIds()),
          ]);
          $room->roomId = $result['room_id'];
  
          return $room;
      }
docs: グループチャットを新規作成.
  
  @param Room             $room
  @param MemberCollection $members
  
  @return Room