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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 checksum(self):
 """ Returns an MD5 digest of the model. This can be used to easily identify whether two models have the same architecture. """

        
        m = md5()
        for hl in self.hidden_layers:
            m.update(str(hl.architecture))
        m.update(str(self.top_layer.architecture))
        return m.hexdigest()