human
Solve the following python programming problem given the following code:
def _get_margin_width(self, cli, margin) : 
    '
        Return the width for this margin.
        (Calculate only once per render time.)
        ' 
    def get_ui_content() : 
        return self._get_ui_content (cli, width = 0, height = 0) 
def get_width() : 
        return margin.get_width (cli, get_ui_content) 
key = (margin, get_width.render_counter) 
    return self._margin_width_cache.get (key, get_width) 

    
    

    Fix the buggy line: key = (margin, get_width.render_counter)
assistant
#Here is Python program to fix the buggy line: key = (margin, get_width.

key = (margin, cli.render_counter)