expected.css

._a_ {
	background: url({./module});
	background: url({./module});
	background: url("{./module module}");
	background: url("{./module module}");
	background: url({./module});
	background: url({./module}#?iefix);
	background: url("#hash");
	background: url("#");
	background: url(data:image/png;base64,AAA);
	background: url(http://example.com/image.jpg);
	background: url(//example.com/image.png);
	background: green url(data:image/png;base64,AAA) url(http://example.com/image.jpg) url(//example.com/image.png) url({./module}) xyz;
}