url(foo.png)
url('foo.png')
url("foo.png")
url('foo\
bar.png')
url("foo\
bar.png")

----------------------------------------------------

[
	["url", "url(foo.png)"],
	["url", "url('foo.png')"],
	["url", "url(\"foo.png\")"],
	["url", "url('foo\\\r\nbar.png')"],
	["url", "url(\"foo\\\r\nbar.png\")"]
]

----------------------------------------------------

Checks for url(), unquoted, single-quoted and double-quoted.