def buy(self, **kwargs):
return self.create_instance(kwargs)<EOL>
Buy a dedicated number and assign it to the specified account.
Returns :class:`Number` object contains id and link to Number.

:Example:

number = client.numbers.create(phone="16463501784", country="US", userId="111")

:param str phone:   Desired dedicated phone number in international E.164 format. Required.
:param str country: Dedicated number country. Required.
:param str userId:  User ID this number will be assigned to. Required.