@SuppressWarnings("AccessStaticViaInstance")
    public static UserPropertyProvider getUserPropertyProvider() {
        return UserManagerContainer.instance.propertyProvider;
    }
Returns the currently-installed UserPropertyProvider.

<b>Warning:</b> in virtually all cases the user property provider should not be used directly. Instead, use the
Map returned by {@link User#getProperties()} to create, read, update or delete user properties. Failure to do so
is likely to result in inconsistent data behavior and race conditions. Direct access to the user property
provider is only provided for special-case logic.

@return the current UserPropertyProvider.
@see User#getProperties
xmppserver/src/main/java/org/jivesoftware/openfire/user/UserManager.java