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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 connect(self, chassis_list):
 """Establish connection to one or more chassis. Arguments: chassis_list -- List of chassis (IP addresses or DNS names) Return: List of chassis addresses. """

        self._check_session()
        if not isinstance(chassis_list, (list, tuple, set, dict, frozenset)):
            chassis_list = (chassis_list,)

        if len(chassis_list) == 1:
            status, data = self._rest.put_request(
                'connections', chassis_list[0])
            data = [data]
        else:
            params = {chassis: True for chassis in chassis_list}
            params['action'] = 'connect'
            status, data = self._rest.post_request('connections', None, params)
        return data