After having loaded a graph from RDBMS tables, I started doing some analysis and realized that there are no null values into graph. I studied the documentation and came up with
https://docs.oracle.com/cd/E56133_01/latest/reference/loader/graph-config/index.html
where in the description of parameter default is stated that:
"If no default is present (null), non-existent properties will contain default Java types (primitives) or empty string (string) or 01.01.1970 00:00 (date)."
I have studied further the documentation and I have not been able to find any option to store nulls into the graph. Am I missing something or this is impossible?