class Transformers {

   static Set<String> capabilitiesToTraits(Set<String> capabilities) {
      if(capabilities == null) {
         return ImmutableSet.of();
      }
      ImmutableSet.Builder<String> builder = ImmutableSet.builder();
      capabilities.forEach((s) -> capabilityToTrait(s).ifPresent(builder::add));
      return builder.build();
   }

   private  Transformers();

}