@onovotny It seems System.Uri already throws exceptions when creating the Uri if an invalid string is passed, including an empty or whitespace string. Maybe it would be better to simply use the null conditional operator for the .TrimEnd() added by #615 and let System.Uri handle validating hostUrl? It simplifies the code and provides a more useful exception to the end user in my opinion.

Also worth noting is that if this PR is merged, it may be a breaking change. Users may have depended on the exceptions thrown by System.Uri and this change will break those users' code.

I've updated #615 to use the null-conditional operator so that this pull request can be made optional. Merging #615 without merging this pull request should be safe.