Set the byte stream (a Python file-like object which does not
perform byte-to-character conversion) for this input source.
The SAX parser will ignore this if there is also a character stream
specified, but it will use a byte stream in preference to opening a
URI connection itself.
If the application knows the character encoding of the byte stream,
it should set it with the setEncoding method.
Set the character stream for this input source. (The stream must be
a Python 1.6 Unicode-wrapped file-like that performs conversion to
Unicode strings.)
If there is a character stream specified, the SAX parser will ignore
any byte stream and will not attempt to open a URI connection to the
system identifier.