function isForbiddenType(sType) {
				var aTypes = [ButtonType.Up, ButtonType.Back, ButtonType.Unstyled];
				return aTypes.indexOf(sType) !== -1;
			}
Overriding the setProperty method in order to keep in sync internal aggregations properties.
@override
@param {string} sPropertyName The name of the property being changed
@param {object} vValue The new value
@param {boolean} bSuppressInvalidate Flag indicating of re-rendering should be suppressed
@returns {object} this Instance for chaining.