private static boolean matchesAfterAppendingChar(Lookup lookup, LookupElement item, char c) {
    PrefixMatcher matcher = lookup.itemMatcher(item);
    return matcher.cloneWithPrefix((matcher.getPrefix() + ((LookupImpl)lookup).getAdditionalPrefix()) + c).prefixMatches(item);
  }
private static boolean matchesAfterAppendingChar(Lookup lookup, LookupElement item, char c)