<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def show_plot_methods(self):
 """Print the plotmethods of this instance"""

        print_func = PlotterInterface._print_func
        if print_func is None:
            print_func = six.print_
        s = "\n".join(
            "%s\n    %s" % t for t in six.iteritems(self._plot_methods))
        return print_func(s)