Three implementations of the writer object interface are provided as
examples by this module.  Most applications will need to derive new
writer classes from the NullWriter class.
- NullWriter ()
 - 
A writer which only provides the interface definition; no actions are
taken on any methods.  This should be the base class for all writers
which do not need to inherit any implementation methods.
 
- AbstractWriter ()
 - 
A writer which can be used in debugging formatters, but not much
else.  Each method simply announces itself by printing its name and
arguments on standard output.
 
- DumbWriter ([file[, maxcol = 72]])
 - 
Simple writer class which writes output on the file object passed in
as file or, if file is omitted, on standard output.  The
output is simply word-wrapped to the number of columns specified by
maxcol.  This class is suitable for reflowing a sequence of
paragraphs.
 
guido@python.org