private void checkArgument(String name, TensorType type) {
        if (context.isMissing(name))
            throw new IllegalStateException("Missing argument '" + name + "': Must be bound to a value of type " + type);
        if (! context.get(name).type().isAssignableTo(type))
            throw new IllegalStateException("Argument '" + name + "' must be bound to a value of type " + type);
    }
Sets the default value to use for variables which are not bound

@param value the default value
@return this for chaining
model-evaluation/src/main/java/ai/vespa/models/evaluation/FunctionEvaluator.java