proc clearOperations(self: var Meta) {....raises: [], tags: [], forbids: [].}

proc enqueueOperation(self: var Meta; operation: Operation) {....raises: [],
    tags: [], forbids: [].}

proc id(meta: Meta): EntityId {....raises: [], tags: [], forbids: [].}

proc operations(self: Meta): seq[Operation] {....raises: [], tags: [], forbids: [].}

macro withMeta[T: tuple](t: T): untyped

macro WithMeta[T: tuple](t: typedesc[T]): typedesc