augment /nw:networks/nw:network/nw:node:
    +--rw ac* [name]
       +--rw name                 string
       + ...
       +--rw l2-connection  {ac-common:layer2-ac}?
       |  ...
       +--rw ip-connection  {ac-common:layer3-ac}?
       |  ...
       +--rw routing-protocols
       |  ...
       +--rw oam
       |  ...
       +--rw security
       |  +--rw encryption {vpn-common:encryption}?
       |  |  +--rw enabled?   boolean
       |  |  +--rw layer?     enumeration
       |  +--rw encryption-profile
       |     +--rw (profile)?
       |        +--:(provider-profile)
       |        |  +--rw encryption-profile-ref?   leafref
       |        |  +--rw network-ref?
       |        |          -> /nw:networks/network/network-id
       |        +--:(customer-profile)
       |           +--rw customer-key-chain?  key-chain:key-chain-ref
       +--rw service
          ...