'Associates an Elastic IP to the instance.
:type ip_address: Either an instance of
:class:`boto.ec2.address.Address` or a string.
:param ip_address: The IP address to associate
with the instance.
:rtype: bool
:return: True if successful'

def use_ip(self, ip_address, dry_run=False):

    if isinstance(ip_address, Address):
        ip_address = ip_address.public_ip
    return self.connection.associate_address(self.id, ip_address, dry_run=dry_run)
