for a map such as `{ 1 {:a "b"} }`, calling `transform-keys ->kebab-case-keyword` would throw an exception since it tries to symbolize the numerical key. ```(cske/transform-keys csk/->kebab-case-keyword { 1 {:a "b"} }) ClassCastException java.lang.Long cannot be cast to clojure.lang.Named clojure.core/name (core.clj:1587) ``` The desirable result is that numerical keys are kept in tact and only text keys are converted.