Does "--config-drive" option of "openstack server create" command accept non-boolean value?

Issue

• The help of openstack server create says that --config-drive option accepts a volume.

(overcloud) [stack@undercloud-0 ~]$ openstack server create -h
usage: openstack server create [-h] [-f {json,shell,table,value,yaml}]
 :
  --config-drive <config-drive-volume>|True
                        Use specified volume as the config drive, or 'True' to
                        use an ephemeral drive

However, it fails when a non-boolean value is specified like this.

(overcloud) [stack@undercloud-0 ~]$ openstack server create --config-drive testvol1 --flavor m1.nano --image cirros-0.4.0-x86_64-disk.img "testvm1"
Invalid input for field/attribute config_drive. Value: testvol1. 'testvol1' is not one of [True, 'True', 'TRUE', 'true', '1', 'ON', 'On', 'on', 'YES', 'Yes', 'yes', False, 'False', 'FALSE', 'false', '0', 'OFF', 'Off', 'off', 'NO', 'No', 'no'] (HTTP 400) (Request-ID: req-UUID)