Steps:

1. Custom interface is added via API
2. No implementation is added / No artifact details are added
3. VFC is used in a service template + implementation details are added here
4. Template fails TOSCA parsing in SO , due to the extended notation.

"Modify" interface has been added to virtNetworkserv VFC

In "resource-Virtnetworkserv-template.yml" , the interface is defined - 

    interfaces:
      Modify:
        type: com.company.so.interfaces.node.lifecycle.Modify
        Modify:
          implementation:
            primary:
              file: ''
      Standard:
        type: tosca.interfaces.node.lifecycle.Standard
        create:
          implementation: workflow/nsCreate
        configure:
          implementation: workflow/nsConfigure
        delete:
          implementation: workflow/nsDelete
    requirements: 

We are expecting the format for the new interface to be same as Standard operations