8. The method of claim 7 , wherein the approximated record type comprises at least one data field and a virtual method whose type includes the type variable bound by the existential type for which the approximated record type was generated.
7. The method of claim 1 , wherein generating the existential type that binds the type variable with sub-classing bounds comprises: generating an approximated record type to be associated with the type variable with sub-classing bounds.