'This command will allow you, if you are a reseller, to change the
userid on a domain name to another userid in your account ONLY if that
new userid is already created.
:param domain: Domain name.
:type  domain: ``str``
:param user_id: The new userid to connect to the domain name.
:type  user_id: ``str``
:rtype: ``bool``
For more info, please see:
https://www.worldwidedns.net/dns_api_protocol_transfer.asp'

def ex_transfer_domain(self, domain, user_id):

    if (self.reseller_id is None):
        raise WorldWideDNSError('This    is    not    a    reseller    account', driver=self)
    params = {'DOMAIN': domain, 'NEW_ID': user_id}
    response = self.connection.request('/api_dns_transfer.asp', params=params)
    return response.success()
