@type t() :: %Cyphi.GroupMembership{
  group: map() | nil,
  group_id: integer() | nil,
  id: integer() | nil,
  join_type: String.t() | nil,
  joined_at: DateTime.t() | nil,
  last_visited_at: DateTime.t() | nil,
  user: map() | nil,
  user_id: integer()
}