Same as <code>expand</code> method but transforms output into
Emmet snippet
@param {String} abbr
@param {String} syntax
@returns {String}
function(abbr, syntax) {
			var snippet = this.expand(abbr, null, syntax);
			if (_.isArray(snippet)) {
				return snippet.join('\n');
			}
			
			if (!_.isString(snippet))
				return snippet.data;
			
			return String(snippet);
		}