docs: function(value) {
  			var vendors = this._vendors;
  			var element = document.documentElement;
  			value = String(value);
  			if (value && value.contains("-beta-")) {
  				var parts = [];
  				value.split(", ").forEach(function(part) {
  					if ((part = part.trim()).startsWith("-beta-")) {
  						vendors.every(function(vendor) {
  							var test = this._camelcase(part.replace("-beta-", vendor));
  							if (element.style[test] !== undefined) {
  								parts.push(part.replace("-beta-", vendor));
  								return false;
  							}
  							return true;
  						}, this);
  					} else {
  						parts.push(part);
  					}
  				}, this);
  				value = parts.join(",");
  			}
  			return value;
  		}