code: @Override
      public Set<Class> getTypesHandledByFactories() {
          final ImmutableSet.Builder<Class> builder = ImmutableSet.builder();
          for (ParameterFactory factory : factories) {
              builder.add(factory.getType());
          }
          return builder.build();
      }
docs: Gets the current set of classes that can be instantiated using an available
  {@link org.wisdom.api.content.ParameterFactory}. This set if dynamic, the returned collection is an immutable
  copy of a snapshot.
  
  @return the set of classes that can be instantiated using an available {@link org.wisdom.api.content
  .ParameterFactory} service.