How to merge two opeanai streams into one stream?

let allstream = {
stream1: "",
stream2: "",
}

 const stream1 = await openai.beta.chat.completions.stream({
    model: 'gpt-4',
    messages: [{ role: 'user', content: 'Say this is a test' }],
    stream: true,
  });

  for await (const chunk of stream1) {
    allstream.stream1 += chunk.choices[0]?.delta?.content
  }

 const stream2 = await openai.beta.chat.completions.stream({
    model: 'gpt-4',
    messages: [{ role: 'user', content: 'Say this is a test' }],
    stream: true,
  });

  for await (const chunk of stream2) {
    allstream.stream2 += chunk.choices[0]?.delta?.content
  }

How to Stream allstream to the client in real-time