SAX.setDocumentLocator()
SAX.startDocument()
SAX.internalSubset(doc, , )
SAX.elementDecl(doc, 4, ...)
SAX.elementDecl(a, 3, ...)
SAX.elementDecl(b, 3, ...)
SAX.startElement(doc)
SAX.startElement(a)
SAX.characters(This, 4)
SAX.endElement(a)
SAX.startElement(b)
SAX.characters( is a valid document, 20)
SAX.endElement(b)
SAX.endElement(doc)
SAX.endDocument()