@Override
  public @NotNull FileBasedIndex.InputFilter getInputFilter() {
    return new DefaultFileTypeSpecificInputFilter(XmlFileType.INSTANCE) {
      @Override
      public boolean acceptInput(final @NotNull VirtualFile file) {
        return "xsd".equals(file.getExtension());
      }
    };
  }
@Override
  public @NotNull FileBasedIndex.InputFilter getInputFilter()