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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 get_unassociated_eip_address(domain='standard', region=None, key=None,
                                 keyid=None, profile=None):
    '''
    Return the first unassociated EIP

    domain
        Indicates whether the address is an EC2 address or a VPC address
        (standard|vpc).

    CLI Example:

    .. code-block:: bash

        salt-call boto_ec2.get_unassociated_eip_address

    .. versionadded:: 2016.3.0
    '''
    eip = None
    for address in get_all_eip_addresses(region=region, key=key, keyid=keyid,
                                         profile=profile):
        address_info = get_eip_address_info(addresses=address, region=region,
                                            key=key, keyid=keyid,
                                            profile=profile)[0]
        if address_info['instance_id']:
            log.debug('%s is already associated with the instance %s',
                      address, address_info['instance_id'])
            continue

        if address_info['network_interface_id']:
            log.debug('%s is already associated with the network interface %s',
                      address, address_info['network_interface_id'])
            continue

        if address_info['domain'] == domain:
            log.debug(
                "The first unassociated EIP address in the domain '%s' is %s",
                domain, address
            )
            eip = address
            break

    if not eip:
        log.debug('No unassociated Elastic IP found!')

    return eip