code: public Set<String> getPropAsCaseInsensitiveSet(String key) {
      return ImmutableSortedSet.copyOf(String.CASE_INSENSITIVE_ORDER, LIST_SPLITTER.split(getProp(key)));
    }
docs: Get the value of a property as a case insensitive {@link Set} of strings.
  
  @param key property key
  @return value associated with the key as a case insensitive {@link Set} of strings