@Nullable
  XmlAttribute getAttribute(@Nullable String qname) {
    if (qname == null) return null;
    final XmlAttribute[] attributes = myTag.getAttributes();

    final boolean caseSensitive = myTag.isCaseSensitive();

    for (final XmlAttribute attribute : attributes) {
      final ASTNode child = XmlChildRole.ATTRIBUTE_NAME_FINDER.findChild(attribute.getNode());
      if (child instanceof LeafElement attrNameElement) {
        if ((caseSensitive && Comparing.equal(attrNameElement.getChars(), qname) ||
             !caseSensitive && Comparing.equal(attrNameElement.getChars(), qname, false))) {
          return attribute;
        }
      }
    }
    return null;
  }
@Nullable
  XmlAttribute getAttribute(@Nullable String qname)