function getRangeForPrevItemInCSS(rule, offset, selRange) {
						var tree = cssEditTree.parse(rule, {
							offset: offset
						});

						return matchedRangeForCSSProperty(tree, selRange, true);
					}
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