public abstract void Subtract(TimePayload <T> payload);
public override void Add(TimePayload <object> payload) { }
public abstract void Add(TimePayload <T> payload);
public override void Subtract(TimePayload <object> payload) { }
public abstract void Subtract(TimePayload <T> payload);
public override void Add(TimePayload <object> payload) { }
public abstract void Add(TimePayload <T> payload);
public override void Subtract(TimePayload <object> payload) { }