@Override
	public void write(EvaluationContext context, Object target, String name, Object newValue) throws AccessException {
		throw new UnsupportedOperationException("Tuple is immutable");
	}
Return an integer if the String property name can be parsed as an int, or null otherwise.
spring-xd-tuple/src/main/java/org/springframework/xd/tuple/spel/TuplePropertyAccessor.java