Ipv4 container enforces mandatory behaviour for addresses sub-container by its structure. This leads to NullPointer exceptions while initializing/writing Ipv4 container.

Model request

PUT - http://localhost:8181/restconf/config/ietf-interfaces:interfaces/interface/local0

"interface":{
"name":"local0",
"type": "iana-if-type:ethernetCsmacd",
"enabled":"true",
"ipv4":{

• --missing address block here*
  "neighbor": { "ip":"192.168.2.1", "link-layer-address":"aa:aa:aa:aa:aa:aa" }

  }
  }

leads to null pointer ,but not by obvious use of null object as interable for List in Ipv4Customizer(line 100),but because proxy objects thats is hidden behind Ipv4 container interface does not have present sub-container for Addresses and throws NullPointerException. This all is cause by attempt to writer container Addresses by writer of Ipv4 whitch is by itself wrong design.