code: function getRangeForPrevItemInCSS(rule, offset, selRange) {
  		var tree = cssEditTree.parse(rule, {
  			offset: offset
  		});
  
  		return matchedRangeForCSSProperty(tree, selRange, true);
  	}
docs: Returns range for item to be selected in CSS before current caret
  (selection) position
  @param {String} rule CSS rule declaration
  @param {Number} offset Rule's position index inside content
  @param {Range} selRange Selection range
  @return {Range} Returns range if previous item was found, <code>null</code> otherwise