static Multimap<String, Range<Integer>> extractHighlightRanges(Map<String, List<String>> highlight) {
        if (highlight == null || highlight.isEmpty()) {
            return ImmutableListMultimap.of();
        }
        final ImmutableListMultimap.Builder<String, Range<Integer>> builder = ImmutableListMultimap.builder();
        highlight.forEach((key, value) -> extractRange(value).forEach(range -> builder.put(key, range)));
        return builder.build();
    }
@Test
    public void simpleHighlightAtStartOfString() throws Exception {
        final Map<String, List<String>> highlights = ImmutableMap.of(
                "message", ImmutableList.of("<em>last</em> message repeated 2 times")
        );

        final Multimap<String, Range<Integer>> result = HighlightParser.extractHighlightRanges(highlights);

        assertThat(result).isNotNull();
        assertThat(result.get("message"))
                .isNotEmpty()
                .containsExactly(Range.closed(0, 4));
    }