import '../../../assert/js/assert.js';
import '../PhetioIDUtils.js';
import '../../../globals.js';
import IOType from './IOType.js';
declare const NullableIO: <ParameterType, ParameterStateType extends PatternStateSelfType, PatternStateSelfType>(parameterType: IOType<ParameterType, ParameterStateType, PatternStateSelfType>) => IOType;
export default NullableIO;
//# sourceMappingURL=NullableIO.d.ts.map