src/sap.m/src/sap/m/MenuButton.js
function isForbiddenType(sType) {
				var aTypes = [ButtonType.Up, ButtonType.Back, ButtonType.Unstyled];
				return aTypes.indexOf(sType) !== -1;
			}
function isForbiddenType(sType) {
				var aTypes = [ButtonType.Up, ButtonType.Back, ButtonType.Unstyled];
				return aTypes.indexOf(sType) !== -1;
			}
function isForbiddenType ( sType ) { var aTypes = [ ButtonType . Up , ButtonType . Back , ButtonType . Unstyled ] ; return aTypes . indexOf ( sType ) !== - 1 ; }
Several button type property values are not allowed
Several button type property values are not allowed