def halt(self, subid, params=None):
        ''' /v1/server/halt
        POST - account
        Halt a virtual machine. This is a hard power off (basically, unplugging
        the machine). The data on the machine will not be modified, and you
        will still be billed for the machine. To completely delete a
        machine, see v1/server/destroy

        Link: https://www.vultr.com/api/#server_halt
        '''
        params = update_params(params, {'SUBID': subid})
        return self.request('/v1/server/halt', params, 'POST')
/v1/server/halt
        POST - account
        Halt a virtual machine. This is a hard power off (basically, unplugging
        the machine). The data on the machine will not be modified, and you
        will still be billed for the machine. To completely delete a
        machine, see v1/server/destroy

        Link: https://www.vultr.com/api/#server_halt