This library currently uses a class from Hibernate and my guess is that in order to keep the size of the lib small this class has been copied from hibernate into an org.hibernate.validator.internal.util package.
The problem is that using this package name in this library means it can not be used in a modular way with other libraries that depend on hibernate due to a package name conflict.

This library should either depend on hibernate or place this class somewhere within its own namespace (com.antkorwin.xsync).