This interface adds four extra methods to the XMLReader
interface that allow XML parsers to support incremental
parsing. Support for this interface is optional, since not all
underlying XML parsers support this functionality.
When the parser is instantiated it is ready to begin accepting
data from the feed method immediately. After parsing has been
finished with a call to close the reset method must be called to
make the parser ready to accept new data, either from feed or
using the parse method.
Note that these methods must _not_ be called during parsing, that
is, after parse has been called and before it returns.
By default, the class also implements the parse method of the XMLReader
interface using the prepareParser, feed and close methods of the
IncrementalParser interface as a convenience to SAX 2.0 driver
writers.
This method is called when the entire XML document has been passed to the parser through the feed method, to notify the parser that there are no more data.