@protocol FooProto @property int bar; @end @protocol AnotherProto @end Class _Nonnull processFooType(Class _Nonnull); Class _Nonnull processComboType(Class _Nonnull); Class _Nonnull processComboType2(Class _Nonnull); @protocol SubProto @end @interface ProtocolTestingBase @end @interface SubProtoImpl: ProtocolTestingBase @end