SAX.setDocumentLocator()
SAX.startDocument()
SAX.internalSubset(doc, , )
SAX.attributeDecl(elem, xmlns, 1, 4, urn:def2, ...)
SAX.attributeDecl(elem, xmlns:a, 1, 4, urn:a2, ...)
SAX.externalSubset(doc, , )
SAX.startElement(doc, xmlns='urn:def', xmlns:a='urn:a')
SAX.characters(
    , 5)
SAX.startElement(elem)
SAX.endElement(elem)
SAX.characters(
, 1)
SAX.endElement(doc)
SAX.endDocument()
