Allow lists starting with a comma should be parsed correctly.

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".


Sending GET request with custom headers.
PASS xhr.send(null) is undefined.
PASS response['x-print'] is "unicorn"
PASS response['y-print'] is "narwhal"
Sending PUT request.
PASS xhr.send(null) is undefined.
PASS successfullyParsed is true

TEST COMPLETE