function normalizeCssArray(val) {
	        if (typeof (val) === 'number') {
	            return [val, val, val, val];
	        }
	        var len = val.length;
	        if (len === 2) {
	            // vertical | horizontal
	            return [val[0], val[1], val[0], val[1]];
	        }
	        else if (len === 3) {
	            // top | horizontal | bottom
	            return [val[0], val[1], val[2], val[1]];
	        }
	        return val;
	    }
Normalize css liked array configuration
e.g.
 3 => [3, 3, 3, 3]
 [4, 2] => [4, 2, 4, 2]
 [4, 3, 2] => [4, 3, 2, 3]
@param {number|Array.<number>} val
@return {Array.<number>}