code: public static Object field(Object subject, int fieldNo)
  	{
  		if (subject instanceof Tuple)
  		{
  			Tuple tuple = (Tuple) subject;
  
  			return tuple.get(fieldNo);
  		} else
  		{
  			throw new IllegalArgumentException("Method is only supported for "
  					+ Tuple.class);
  		}
  	}
docs: /* @ helper @