vim-id in AAI is handled as a mandatory parameter

In AAI esr-vnfm: object

 - vim-id: string indicate the VIM to deploy VNF.

The vim-id is just an indication where to deploy the VNF by default, but it is not a mandatory parameter.

• the def select_vnfm(vnfm_type, vim_id): in vfc/nfvo/lcm/lcm/pub/msapi/extsys.py makes it mandatory to fill out the VIM id. 
• the same problem arises when the VNFM information is deserialised (mandatory)

2018-05-07 09:11:17,854:[lcm.ns.vnfs.views]:[views.py]-[274] [ERROR]:{'vimId': [u'This field may not be blank.']}
2018-05-07 09:11:17,855:[lcm.ns.vnfs.views]:[views.py]-[275] [ERROR]:Traceback (most recent call last):
File "/service/vfc/nfvo/lcm/lcm/ns/vnfs/views.py", line 268, in get
raise Exception(resp_serializer.errors)
Exception: {'vimId': [u'This field may not be blank.']}

If VF-C uses the vimId parameter to limit the scope of the VNFM, than one VNFM is limited to a single cloud instance.

Could someone from VF-C team comment what is the expected behaviour?

1. Make vim-id in AAI mandatory
2. If the vim-id is empty than the VNFM is not limited to that single cloud (preferred)