human
Solve the following python programming problem given the following code:
def add_to_canvas(self, canvas, traces, legend = False, **kwargs) : 
    (figure, row, col) = canvas 
    def append_annotation(a, xref, yref) : 
        if ('xref' not in a) : 
            a ['xref'] = xref 
if ('yref' not in a) : 
            a ['yref'] = yref 
figure.layout.annotations.append (a) 
def append_trace(t, row, col) : 
        figure.append_trace (t, row, col) 
def recursive_append(traces) : 
        if isinstance (traces, Annotations) : 
            (xref, yref) = figure._grid_ref [(row - 1)] [(col - 1)] 
            for a in traces : 
                append_annotation (a, xref, yref) 
else : 
            if isinstance (traces, Trace) : 
                try : 
                    append_trace (traces, row, col) 
except PlotlyDictKeyError : 
                    for t in traces : 
                        recursive_append (traces [t]) 
else : 
                if isinstance (traces, dict) : 
                    for t in traces : 
                        recursive_append (traces [t]) 
else : 
                    if isinstance (traces, (tuple, list)) : 
                        for t in traces : 
                            recursive_append (t) 
recursive_append (legend) 
    figure.layout ['showlegend'] = legend 
    return canvas 

    
    

    Fix the buggy line: recursive_append (legend)
assistant
#Here is Python code to fix the buggy line: recursive_append (legend)
.

recursive_append (traces)