Function is

is<TSubject>(
subject: Maybe<TSubject>,
Prototype: ConstructorOf<TSubject>,
): subject is TSubject
Check if something is a concrete value of the given type. Can be used as a typeguard.
Type Parameters
- TSubject
  The type to check against.
Parameters
- subject: Maybe<TSubject>
  The subject that could be nil.
- Prototype: ConstructorOf<TSubject>
  The prototype to check against.
Returns subject is TSubject
true if the input element matches the given type, false otherwise.
- Defined in source/data/nil.ts:35