cow = opts.get : AttributeError: 'NoneType' object has no attribute 'get'" about buttervolume HOT 1 CLOSED

Request: /VolumeDriver.Get {'Name': 'modelyz_store'}" 
Response: {\"Err\": \"modelyz_store: no such volume\"}" 
Request: /VolumeDriver.Capabilities {}"
Response: {\"Capabilities\": {\"Scope\": \"local\"}}"
Request: /VolumeDriver.Get {'Name': 'modelyz_store'}" 
Response: {\"Err\": \"modelyz_store: no such volume\"}" 
Request: /VolumeDriver.Create {'Name': 'modelyz_store', 'Opts': None}" 
Traceback (most recent call last):
  File \"/usr/local/lib/python3.9/dist-packages/bottle-0.12.23-py3.9.egg/EGG-INFO/scripts/bottle.py\", line 876, in _handle
    return route.call(**args)
  File \"/usr/local/lib/python3.9/dist-packages/bottle-0.12.23-py3.9.egg/EGG-INFO/scripts/bottle.py\", line 1756, in wrapper
    rv = callback(*a, **ka)
  File \"/usr/local/lib/python3.9/dist-packages/buttervolume-3.9-py3.9.egg/buttervolume/plugin.py\", line 62, in new_handler
    resp = json.dumps(handler(req))
  File \"/usr/local/lib/python3.9/dist-packages/buttervolume-3.9-py3.9.egg/buttervolume/plugin.py\", line 88, in volume_create
    cow = opts.get(\"copyonwrite\", \"true\").lower()
AttributeError: 'NoneType' object has no attribute 'get'