OGM-618 is fixed but one small glitch remains:

In a hierarchy of nested stuff: user -> address -> address type
address type has a single field, name
now if you set address type to null
what happens is, that the empty sub-document "type {}" remains
thas caused as we receive address.type.name = PUT_NULL in the dialect
but we dont deduct from this that the entire sub-doc should be removed.