I'm not exactly sure if this is what you're looking for, but you could use a for loop to look through all of the values if there is more than one, and concatenate each URL you generate to a string with a newline character, then at the end of the loop return the string.
That would result in one value with multiple URLs, but it wouldn't be an array type. If you wanted to emit an array you could also loop and build an array of URLs. This discuss post asked about something similar.