@Override
    @Nullable
    public Object convert(String value) {
        if (value == null || value.isEmpty()) {
            return null;
        }

        final Parser parser = new Parser(timeZone.toTimeZone());
        final List<DateGroup> r = parser.parse(value);

        if (r.isEmpty() || r.get(0).getDates().isEmpty()) {
            return null;
        }

        return new DateTime(r.get(0).getDates().get(0), timeZone);
    }
@Test
    public void convertUsesEtcUTCIfTimeZoneSettingIsBlank() throws Exception {
        Converter c = new FlexibleDateConverter(ImmutableMap.<String, Object>of("time_zone", " "));

        final DateTime dateOnly = (DateTime) c.convert("2014-3-12");
        assertThat(dateOnly.getZone()).isEqualTo(DateTimeZone.forID("Etc/UTC"));
    }