MIT License
* Usage
** prepare handler class
At first, you have to prepare handler class.
There are two ways for that.
1. implements IXMLSAXHandler interface.
2. extends XMLSAXDefaultHandler class.
**  Implements IXMLSAXHandler interface.
In this case, you should implements all functions IXMLSAXHandler interface indicates.
-- MyHandler.as
package {
import org.coderepos.xml.sax.IXMLSAXHandler;
import org.coderepos.xml.XMLAttributes;
public class MyHandler implements IXMLSAXHandler {
    ...
    public function startDocument():void { ... }
    public function endDocument():void { ... }
    public function startElement(ns:String, name:String, attrs:XMLAttributes, depth:uint):void { ... }
    public function endElement(ns:String, name:String, depth:uint):void { ... }
    public function characters(str:String):void { ... }
    public function comment(str:String):void { ... }
    public function cdata(str:String):void { ... }
}
}
** Extends XMLSAXDefaultHandler class.
You only have to do is extending XMLSAXDefaultHandler, and override functions which you just need.
It is easier than IXMLSAXHandler implementing, but in case that you want to extends another class,
it is incovenient because AS3 doesn't support multiple inheritance.
package {
import org.coderepos.xml.sax.XMLSAXDefaultHandler;
import org.coderepos.xml.XMLAttributes;
public class MyHandler extends XMLSAXDefaultHandler {
    ...
    override public function startElement(ns:String, name:String, attrs:XMLAttributes, depth:uint):void { ... }
    override public function endElement(ns:String, name:String, depth:uint):void { ... }
    override public function characters(str:String):void { ... }
}
}
** If you completed to make your parser class, then, set it as XMLSAXParser's handler
import org.coderepos.xml.sax.XMLSAXParser;
var parser:XMLSAXParser = new XMLSAXParser();
parser.handler = new MyHnadler();
parser.pushBytes(xmlBytesFragment1);
parser.pushBytes(xmlBytesFragment2);
parser.pushBytes(xmlBytesFragment3);
parser.pushBytes(xmlBytesFragment4);
...
** XMLAttributes
on callback named 'startElement', arguments includes XMLAttributes object.
startElement(ns:String, localName:String, attrs:XMLAttributes, depth:uint)
<foo xmlns="https://example.org/" xmlns:bar="https://example.org/bar" hoge="aaa" bar:fuga="bbb">
on this element,
attrs.getValue("hoge"); returns "aaa"
attrs.getValueWithPrefix("bar", "fuga"); returns "bbb"
or you can iterates all attributes
var attrsArray:Array = attrs.toArray();
for each(attr:XMLAttribute in attrsArray) {
    trace(attr.uri);   // namespace uri
    trace(attr.name);  // attribute name
    trace(attr.value); // attribute value
}