func fanIn[T any](inputs ...<-chan T) <-chan T {
	output := make(chan T)
	var wg sync.WaitGroup

	// Increment the wait group for each input channel
	wg.Add(len(inputs))

	// Start a goroutine for each input channel
	for _, input := range inputs {
		go func(ch <-chan T) {
			defer wg.Done()
			for num := range ch {
				output <- num
			}
		}(input)
	}

	// Start a goroutine to wait for all inputs to be closed and then close the output channel
	go func() {
		wg.Wait()
		close(output)
	}()

	return output
}