T A copy of the singleton component.
Gets the value of a singleton component. Note that if querying a singleton component from a system-associated entity, the query must include either EntityQueryOptions.IncludeSystems or the SystemInstance component.
A singleton component is a component of which only one instance exists that satisfies this query.
Additional resources: EntityQuery.SetSingleton, EntityQuery.GetSingletonEntity, EntityQuery.GetSingletonBuffer, ComponentSystemBase.GetSingleton