Setting VLAN on a virtual server

Pulling my hair out trying to enable a VLAN for a virtual server. This is what I'm doing -- "v" is the object reference to LocalLB.VirtualServer:

 

 

 

vlan_filter_list = v.typefactory.create('Common.VLANFilterList')

 

enabled_state = v.typefactory.create('Common.EnabledState')

 

vlan_filter_list.state = enabled_state.STATE_ENABLED

 

vlan_filter_list.vlans = ["external"]

 

v.set_vlan([vip_name], [vlan_filter_list])

 

 

 

Unfortunately, it throws an exception:

 

 

 

xml.sax._exceptions.SAXParseException: :1:49: syntax error

 

 

 

Any ideas? I'm pretty stuck. :(