ForeignInstanceStub is an abstract class that
is implemented by stubs for foreign classes.
It provides convenience methods for managing
cross-references with instances created in the
foreign language environment as well as boiler
plate code for dart ffi bookeeping.
ForeignInterfaceSkel is an abstract class that
is implemented by dart abstract classes that
will provide the skeleton for stups of foreign
interfaces. It provides convenience methods for
managing cross-references with the foreign
interface stups as well as boiler plate code
for dart ffi bookeeping.