@Override
  public void addElement(@NotNull LookupElement element,
                         @NotNull CompletionSorter sorter,
                         @NotNull PrefixMatcher prefixMatcher,
                         @NotNull LookupElementPresentation presentation) {
    registerMatcher(element, prefixMatcher);
    associateSorter(element, (CompletionSorterImpl)sorter);
    addElement(element, presentation);
  }
@Override
  public void addElement(@NotNull LookupElement element,
                         @NotNull CompletionSorter sorter,
                         @NotNull PrefixMatcher prefixMatcher,
                         @NotNull LookupElementPresentation presentation)