code: private Collection<MatchInfo> findTimeZoneNames(String text, int start, EnumSet<GenericNameType> types) {
          Collection<MatchInfo> tznamesMatches = null;
  
          // Check if the target name type is really in the TimeZoneNames
          EnumSet<NameType> nameTypes = EnumSet.noneOf(NameType.class);
          if (types.contains(GenericNameType.LONG)) {
              nameTypes.add(NameType.LONG_GENERIC);
              nameTypes.add(NameType.LONG_STANDARD);
          }
          if (types.contains(GenericNameType.SHORT)) {
              nameTypes.add(NameType.SHORT_GENERIC);
              nameTypes.add(NameType.SHORT_STANDARD);
          }
  
          if (!nameTypes.isEmpty()) {
              // Find matches in the TimeZoneNames
              tznamesMatches = _tznames.find(text, start, nameTypes);
          }
          return tznamesMatches;
      }
docs: Returns a collection of time zone display name matches for the specified types in the
  given text at the given offset. This method only finds matches from the TimeZoneNames
  used by this object.
  @param text the text
  @param start the start offset in the text
  @param types the set of name types.
  @return A collection of match info.