How to read a ExpandedNode data?|OPC UA Implementation: Stacks, Tools, and Samples|Forum|OPC Foundation

I use SessionChannel.browse() get a ReferenceDescription object.ReferenceDescription object's NodeId is instance of ExpandedNodeId.What print is:

 [3]=ReferenceDescription
      ReferenceTypeId=i=0
      IsForward=false
      NodeId=ns=2;s=0:Assets
      BrowseName=null
      DisplayName=null
      NodeClass=NodeClass
        value=0
        name=Unspecified
        ordinal=0
      TypeDefinition=i=0

so,I need to read the Assets node data,how can i get it?

Is there has any way to convert ExpandedNodeId to NodeId?

The lib i use is UA-Java:

org.opcfoundation.ua
opc-ua-stack
1.03.340.0-SNAPSHOT