code: public Collection<String> getNames(Collection<P> properties)
    {
      Preconditions.checkNotNull(properties);
      return Collections2.transform(properties, new Function<P, String>()
      {
        @Override
        public String apply(P property)
        {
          return converter.convert(property);
        }
      });
    }
docs: Returns the property names of the given enum items contained in this
  vocabulary.
  
  @param properties
  a collection of properties to get the name of, must not be
  <code>null</code>
  @return the collection of the names of properties in <code>properties</code>.