// setup batch function
batchFn := func(ctx context.Context, keys dataloader.Keys) []*dataloader.Result {
  var results []*dataloader.Result
  // do some async work to get data for specified keys
  // append to this list resolved values
  return results
}

// create Loader with an in-memory cache
loader := dataloader.NewBatchedLoader(batchFn)

/**
 * Use loader
 *
 * A thunk is a function returned from a function that is a
 * closure over a value (in this case an interface value and error).
 * When called, it will block until the value is resolved.
 */
thunk := loader.Load(context.TODO(), dataloader.StringKey("key1")) // StringKey is a convenience method that make wraps string to implement `Key` interface
result, err := thunk()
if err != nil {
  // handle data error
}

log.Printf("value: %#v", result)