Test EventSource constructor functionality. Should print a series of PASS messages followed by DONE.

PASS: missing argument to EventSource constructor resulted in an exception (TypeError: Not enough arguments)
PASS: passing an empty string to the EventSource constructor resulted in an exception (SyntaxError: The string did not match the expected pattern.)
PASS: passing an invalid URL to the EventSource constructor resulted in an exception (SyntaxError: The string did not match the expected pattern.)
PASS: no exception when passing a second argument to the EventSource constructor
DONE