1SAX.setDocumentLocator()
2SAX.startDocument()
3SAX.internalSubset(doc, , )
4SAX.elementDecl(doc, 4, ...)
5SAX.elementDecl(a, 3, ...)
6SAX.elementDecl(b, 3, ...)
7SAX.externalSubset(doc, , )
8SAX.startElement(doc)
9SAX.startElement(a)
10SAX.characters(This, 4)
11SAX.endElement(a)
12SAX.startElement(b)
13SAX.characters( is a valid document, 20)
14SAX.endElement(b)
15SAX.endElement(doc)
16SAX.endDocument()
17