CommonStreamBeginningMessage<LibObjT> asStreamBeginning() const noexcept;
CommonStreamEndMessage<LibObjT> asStreamEnd() const noexcept;
CommonEventMessage<LibObjT> asEvent() const noexcept;
CommonStreamBeginningMessage<LibObjT> asStreamBeginning() const noexcept;
CommonStreamEndMessage<LibObjT> asStreamEnd() const noexcept;
CommonEventMessage<LibObjT> asEvent() const noexcept;