function fnGetExtensionControllerSync(sControllerName) {
				// sync load Controller extension if necessary
				if (!mRegistry[sControllerName] && !sap.ui.require(sControllerName)) {
					loadControllerClass(sControllerName, sViewId);
				}

				// retrieve legacy controller from registry
				if (mRegistry[sControllerName] !== undefined) {
					return mRegistry[sControllerName];
				} else {
					/* eslint-disable no-loop-func */
					Log.error("Attempt to load Extension Controller " + sControllerName + " was not successful - is the Controller correctly defined in its file?", null, function() {
						return {
							type: "ControllerExtension",
							name: sControllerName
						};
					});
					/* eslint-enable no-loop-func */
					return {};
				}
			}
Retrieves the controller-extension with the given name synchronously.
@param {string} sControllerName the extension controller class name
@returns {Object} loaded controller extension