The generic version of Transformer required the input and output types to be identical. This seemed to me to reduce the usefulness of transformed collections, as transforming one type into another seems like it would be a fairly common operation. I'm not sure how to fix this, however, as it also doesn't seem feasible to have a generic TransformedCollection with different input and output types that implements Collection<E>. Anyway, this patch de-generifies TransformedCollection, which also fixes some compilation problems. Please disregard this change if you disagree and have a better solution.
COLLECTIONS-243, where there is much Transformed* discussion.