@Nullable
        private Double parseGroups(@NonNull final MatcherWrapper matcher, final int first, final int last) {
            final List<String> groups = new ArrayList<>(last - first + 1);
            for (int i = first; i <= last; i++) {
                groups.add(matcher.group(i));
            }

            return parse(groups);
        }
Parses latitude or longitude out of a given range of matched groups.

@param matcher the matcher that holds the matches groups
@param first   the first group to parse
@param last    the last group to parse
@return the parsed latitude/longitude, or null if parsing failed
main/src/main/java/cgeo/geocaching/location/GeopointParser.java