@Override
        public String getBinding(String name) {
            if (wrappedToStringContext != null && wrappedToStringContext.getBinding(name) != null)
                return wrappedToStringContext.getBinding(name);
            else
                return wrappedSerializationContext.getBinding(name);
        }
Returns the resolution of an identifier, or null if it isn't defined in this context
searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/TensorFunctionNode.java