@Override
    public Value evaluate(Context context) {
        throw new RuntimeException("Name nodes should never be evaluated");
    }
An opaque name in a ranking expression. This is used to represent names passed to the context
and interpreted by the given context in a way which is opaque to the ranking expressions.

@author Simon Thoresen Hult
searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/NameNode.java