Returns a single synchronous Promise instance that is already resolved with the given value. If the value passed is
a promise then that promise is returned instead of creating a new synchronous promise instance.
If a new instance is returned then any chained operations will execute synchronously at the point of being
added (calling then()).
Returns a single synchronous Promise instance that is already resolved with the given value. If the value passed is a promise then that promise is returned instead of creating a new synchronous promise instance. If a new instance is returned then any chained operations will execute synchronously at the point of being added (calling
then()).