package operator_test import ( "context" "flux/core" ) type captureEmitter[T any] struct { records []core.StreamRecord[T] } func (e *captureEmitter[T]) Emit(_ context.Context, record core.StreamRecord[T]) error { e.records = append(e.records, record) return nil } func (e *captureEmitter[T]) Records() []core.StreamRecord[T] { result := make([]core.StreamRecord[T], len(e.records)) copy(result, e.records) return result }