selectionChange() {
				// if package field is visible but has no value, the OK button is disable
				if (that._oPackageListItem.getVisible() && !that._oPackage.getValue()) {
					return;
				}

				that.getButtons()[1].setEnabled(true);
				that._oTransport.setValueState(ValueState.None);
			}
Creates the transport <code>sap.m.ComboBox</code>.
@returns {sap.m.ComboBox} Transport <code>sap.m.ComboBox</code>

@private