Outputs a function which will log the arguments to Visdom in an appropriate way.

            Args:
                vis_fn: A function, such as self.vis.image

def _viz_prototype(self, vis_fn):
        ''' Outputs a function which will log the arguments to Visdom in an appropriate way.

            Args:
                vis_fn: A function, such as self.vis.image
        '''
        def _viz_logger(*args, **kwargs):
            self.win = vis_fn(*args,
                              win=self.win,
                              env=self.env,
                              opts=self.opts,
                              **kwargs)
        return _viz_logger