public static XsdNamespaceBuilder computeNamespace(@NotNull Reader reader) {
    try (reader) {
      XsdNamespaceBuilder xsdBuilder = new XsdNamespaceBuilder();
      NanoXmlBuilder builder = xsdBuilder.new NanoBuilder();
      NanoXmlUtil.parse(reader, builder);
      HashSet<String> tags = new HashSet<>(xsdBuilder.getTags());
      tags.removeAll(xsdBuilder.myReferencedTags);
      xsdBuilder.getRootTags().addAll(tags);
      return xsdBuilder;
    }
    catch (IOException e) {
      // can never happen
      throw new RuntimeException(e);
    }
  }
public static XsdNamespaceBuilder computeNamespace(@NotNull Reader reader)