LDIF error message on null

In Framework Core:

A better error message could be provided when a null value has been set in an entity at the connector level. For example when the value is taken from the entity repository and that value turns out to be null.

Error appears in:
Unify.Framework.IO.LDAP\LDIF\LDIFSafeStringFilter.IsSafe
as an argument null exception.

However the value is retrieved in:
Unify.Framework.Adapter.LDIF\AdapterEntityToLDIFAttrvalRecordAdapter.GetLDIFAttrvalSpec