applyChange(oManifest, oChange) {
			if (!oChange.getContent().hasOwnProperty("ach")) {
				throw new Error("No 'Application Component Hierarchy' (ACH) in change content provided");
			}

			if (typeof oChange.getContent().ach !== "string") {
				throw new Error(`The current change value type of property ach is '${typeof oChange.getContent().ach}'. Only allowed type for poperty ach is string`);
			}

			if (!regex.test(oChange.getContent().ach)) {
				throw new Error(`The current change value of property ach is '${oChange.getContent().ach}'. Supported values for property ach is the regular expression ${regex}`);
			}

			ObjectPath.set(["sap.app", "ach"], oChange.getContent().ach, oManifest);
			return oManifest;
		}
Applies <code>appdescr_app_setAch</code> change to the manifest.
@param {object} oManifest - Original manifest
@param {sap.ui.fl.apply._internal.flexObjects.AppDescriptorChange} oChange - Change with type <code>appdescr_app_setAch</code>
@param {object} oChange.content - Details of the change
@param {string} oChange.content.ach - String ach (only allowed regex is ^([a-zA-Z0-9]{2,3})(-[a-zA-Z0-9]{1,6})*$)
@returns {object} Updated manifest with changed <code>appdescr_app_setAch</code>

@private
@ui5-restricted sap.ui.fl.apply._internal