@Nullable
  @Override
  protected String selectString(@NotNull Selector selector, @NotNull Object context) throws Exception {
    if (StringUtil.isEmpty(selector.getPath())) {
      return null;
    }
    XPath xPath = lazyCompile(selector.getPath());
    String s = xPath.valueOf(context); //NON-NLS
    if (s == null) {
      throw new Exception(String.format("XPath expression '%s' doesn't match", xPath.getXPath()));
    }
    return s;
  }
@Nullable
  @Override
  protected String selectString(@NotNull Selector selector, @NotNull Object context)