'Attach a volume identified by the volume ID to the given server ID
:param server_id: The ID of the server
:param volume_id: The ID of the volume to attach.
:param device: The device name (optional)
:param tag: The tag (optional)
:rtype: :class:`Volume`'

@api_versions.wraps('2.49')
def create_server_volume(self, server_id, volume_id, device=None, tag=None):

    body = {'volumeAttachment': {'volumeId': volume_id}}
    if (device is not None):
        body['volumeAttachment']['device'] = device
    if (tag is not None):
        body['volumeAttachment']['tag'] = tag
    return self._create(('/servers/%s/os-volume_attachments' % server_id), body, 'volumeAttachment')
