A helper (mixin) class to provide external references in an R/S-Plus portable way.
A virtual Class: No objects may be created from it.
Id:Object of class "integer"
this is an integer vector holding an opaque reference into a C struct
(may or may not be a C pointer, may or may not have length one).
signature(from = "dbObjectId", to = "integer"): ...
signature(from = "dbObjectId", to = "numeric"): ...
signature(from = "dbObjectId", to = "character"): ...
signature(x = "dbObjectId"): ...
signature(x = "dbObjectId"): ...
signature(object = "dbObjectId"): ...