Shorthand method for retrieving a single Subject by its
@id, if it exists.
a promise resolving to the requested Subject, or
undefined if not found
Actively reads data from the domain.
The query executes in response to either subscription to the returned
result, or calling
All results are guaranteed to derive from the current state; however since the observable results are delivered asynchronously, the current state is not guaranteed to be live in the subscriber. In order to keep this state alive during iteration (for example, to perform a consequential operation), perform the read in the scope of a read procedure.
the declarative read description