code: def print_topics(self, header, cmds, cmdlen, maxcol):
          
          if header:
              if cmds:
                  self.stdout.write("%s\n" % str(header))
                  if self.ruler:
                      self.stdout.write("%s\n" % str(self.ruler * len(header)))
                  self.columnize(cmds, maxcol - 1)
                  self.stdout.write("\n")
docs: Override 'print_topics' so that you can exclude EOF and shell.
              2016-02-12: added to test, copied from
              https://github.com/xlcnd/isbntools/blob/master/isbntools/bin/repl.py