@Override
	public String getRawString(int index) {
		Object rawValue = values.get(index);
		if (rawValue != null) {
			String value = convert(rawValue, String.class);
			if (value != null) {
				return value;
			}
			else {
				return null;
			}
		}
		else {
			return null;
		}
	}
@param index the index of the value
@return the converted raw value, trimmed
spring-xd-tuple/src/main/java/org/springframework/xd/tuple/DefaultTuple.java