private @NotNull String getDoctype() {
    if (myHtml4RadioButton.isSelected()) {
      return XmlUtil.XHTML4_SCHEMA_LOCATION;
    }
    if (myHtml5RadioButton.isSelected()) {
      return Html5SchemaProvider.getHtml5SchemaLocation();
    }
    return myDoctypeTextField.getText();
  }
private @NotNull String getDoctype()