The {@link NullValue setNullValue()} attribute can be set to any valid
value (based on property type). The {@link NullValue setNullValue()} attribute
is used to specify an inbound null value replacement. What this means is
that when the value is detected in the object property, a NULL will be written
to the database (the opposite behavior of an inbound null value replacement).
This allows you to use a magic null number in your application for types that
do not support null values (such as int, double, float). When these types of
properties contain a matching null value (for example, say, -9999), a NULL
will be written to the database instead of the value.