The Can Opener
Often some family of brands have no proprietary interests to protect from each other and we invented the can opener for such a family.
A can opener will try to open a domain by invoking each domain creator whose brander is in the family.
If it succeeds it instals a DDT and reports the real type of the opened object.
An unimplemented recent idea is to include creators outside the family.
The opener recalls that such creators are not of the family and reports the type by numeric code, probably the alleged key type.