While a runtime specializer may always be able to generate an automated specialized version of a generic class, in some cases an alternate form of user control over specialization may allow the use of automated specialization while also adding (or overriding) specialization-specific method implementations. In general, the set of members of a generic class may not change when the class is specialized. In other words, the same members may exist in the auto-specialized version as in the generic version. However, manual refinement of specialized classes may allow a developer to hand specialize a particular (possibly a better) representation and/or implementation of one or more methods of the specialized class.