Adds prerequisite_type to the list of prerequisites of interface_type.
This means that any type implementing interface_type must also implement
prerequisite_type. Prerequisites can be thought of as an alternative to
interface derivation (which GType doesn't support). An interface can have
at most one instantiatable prerequisite type.
Adds
prerequisite_typeto the list of prerequisites ofinterface_type. This means that any type implementinginterface_typemust also implementprerequisite_type. Prerequisites can be thought of as an alternative to interface derivation (which GType doesn't support). An interface can have at most one instantiatable prerequisite type.