code: function (moduleName, modulePath, contents) {
  					if (contents.indexOf("require(") < 0) { return contents; }
  					if (modules.indexOf(moduleName) < 0) { return contents; }
  					var start = "", end = "";
  					layers.forEach(function (l) {
  						start += "require([\"" + l.name + "\"], function () {\n";
  						end += "\n});";
  					});
  					return contents.replace("require(", start + "require(") + end;
  				}
docs: Specify a callback to be called for writing down app root modules content. The callback wraps modules content into several nested 'require' calls (one for each layer modules)