@mixin foobar
@media (min-width: 600px)
	@include foobar

=foobar
+foobar

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

[
	["atrule-line", [
		["atrule", "@mixin"],
		" foobar"
	]],
	["atrule-line", [
		["atrule", "@media"],
		" (min-width: 600px)"
	]],
	["atrule-line", [
		["atrule", "@include"],
		" foobar"
	]],
	["atrule-line", [
		["atrule", "="],
		"foobar"
	]],
	["atrule-line", [
		["atrule", "+"],
		"foobar"
	]]
]

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

Checks for at-rules.