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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def save_graph(cn_topo, filename, showintfs=False, showaddrs=False):
    '''
    Save the topology to an image file 
    '''
    __do_draw(cn_topo, showintfs=showintfs, showaddrs=showaddrs)
    pyp.savefig(filename)