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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 node_done(self, ssid=None):
 """ Release the servers for the specified ssid. The API doesn't provide any kind of output, try to be helpful by providing the list of servers to be released. :param ssid: ssid of the server pool :return: [ requested_hosts ] """

        if self.api_key is None:
            raise exceptions.ApiKeyRequired

        if ssid is None:
            raise exceptions.SsidRequired

        # There is no body replied in this call so at least get the hosts for
        # the specified ssid to return them.
        requested_hosts = dict()
        for host in self.self_inventory:
            if ssid == self.self_inventory[host]['comment']:
                requested_hosts[host] = self.full_inventory[host]

        args = "key={key}&ssid={ssid}".format(key=self.api_key, ssid=ssid)

        resp, body = self.get('Node/done?%s' % args)

        return requested_hosts