private void parseAttribute() {
    assert token() == XML_NAME;
    final PsiBuilder.Marker att = mark();
    advance();
    if (token() == XML_EQ) {
      advance();
      parseAttributeValue();
    }
    else {
      error(XmlPsiBundle.message("xml.parsing.expected.attribute.eq.sign"));
    }
    att.done(XML_ATTRIBUTE);
  }
private void parseAttribute()