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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 add_ip_address(list_name, item_name):
    '''
    Add an IP address to an IP address list.

    list_name(str): The name of the specific policy IP address list to append to.

    item_name(str): The IP address to append to the list.

    CLI Example:

    .. code-block:: bash

        salt '*' bluecoat_sslv.add_ip_address MyIPAddressList 10.0.0.0/24

    '''
    payload = {"jsonrpc": "2.0",
               "id": "ID0",
               "method": "add_policy_ip_addresses",
               "params": [list_name, {"item_name": item_name}]}

    response = __proxy__['bluecoat_sslv.call'](payload, True)

    return _validate_change_result(response)