StreamRecoder instances translate data from one encoding to another.
They use the complete set of APIs returned by the
codecs.lookup() function to implement their task.
Data written to the StreamRecoder is first decoded into an
intermediate format (depending on the "decode" codec) and then
written to the underlying stream using an instance of the provided
Writer class.
In the other direction, data is read from the underlying stream using
a Reader instance and then encoded and returned to the caller.