packages/@aws-cdk/example-construct-library/lib/index.ts

// The index.ts files contains a list of files we want to
// include as part of the public API of this module.
// In general, all files including L2 classes will be listed here,
// while all files including only utility functions will be omitted from here.

// obviously, the ExampleResource L2 should be exported
export * from './example-resource';

// notice that private/example-resource-common.ts is not exported!