There is no expression-based PropertyRef method in OneToOne mapping, what is standard in other mapping-by-code mappings, i.e. Key mapping.
There is MethodInfo-typed PropertyReference instead - this name and input type is not present in any other part of mapping.
It will be good to unify the latter with the former for consistency.
Merged to master 4bb74a8cd71eda90e6e918d04535ac81c5a4cecc