Returns a salt to be used by the {@link HashService} during hash computation, or {@code null} if no salt is
provided as part of the request.
<p/>
Note that a {@code null} value does not necessarily mean a salt won't be used at all - it just
means that the request didn't include one. The servicing {@link HashService} is free to provide a salting
strategy for a request, even if the request did not specify one.
@return a salt to be used by the {@link HashService} during hash computation, or {@code null} if no salt is
provided as part of the request.
Returns a salt to be used by the {@link HashService} during hash computation, or {@code null} if no salt is provided as part of the request. <p/> Note that a {@code null} value does not necessarily mean a salt won't be used at all - it just means that the request didn't include one. The servicing {@link HashService} is free to provide a salting strategy for a request, even if the request did not specify one.
@return a salt to be used by the {@link HashService} during hash computation, or {@code null} if no salt is provided as part of the request.