human
Solve the following python programming problem given the following code:
def _draw_treecycle(self) : 
    if (len (self._treetoks) <= 1) : 
        return 
label = ('%d Trees' % len (self._treetoks)) 
    c = c._tree_canvas 
    margin = ChartView._MARGIN 
    right = (((self._chart.num_leaves () * self._unitsize) + margin) - 2) 
    tag = c.create_text (right, 2, anchor = 'ne', text = label, font = self._boldfont) 
    self._tree_tags.append (tag) 
    (_, _, _, y) = c.bbox (tag) 
    for i in range (len (self._treetoks)) : 
        x = (right - (20 * ((len (self._treetoks) - i) - 1))) 
        if (i == self._treetoks_index) : 
            fill = '#084' 
else : 
            fill = '#fff' 
tag = c.create_polygon (x, (y + 10), (x - 5), y, (x - 10), (y + 10), fill = fill, outline = 'black') 
        self._tree_tags.append (tag) 
        def cb(event, self = self, i = i) : 
            self._treetoks_index = i 
            self.draw_tree () 
c.tag_bind (tag, '<Button-1>', cb) 

    
    

    Fix the buggy line: c = c._tree_canvas
assistant
#Here is Python code to fix the buggy line: c = c.

c = self._tree_canvas