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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 backend_add(cls, name, backend):
 """ Add a backend into a webaccelerator """

        oper = cls.call(
            'hosting.rproxy.server.create', cls.usable_id(name), backend)
        cls.echo('Adding backend %s:%s into webaccelerator' %
                 (backend['ip'], backend['port']))
        cls.display_progress(oper)
        cls.echo('Backend added')
        return oper