Incorrect Cost Calculation While Streaming?

client.chat.completions.create(
    model="gpt-4o",
    max_tokens=100,
    messages=[
        {"role": "system", "content": "You are a great storyteller."},
        {"role": "user", "content": "Once upon a time in a galaxy far, far away..."}
    ],
    stream=True,
    stream_options={
        "include_usage": True # set to true
    }
)

openai.chat.completions.create({
  messages: [
    {
      role: "user",
      content: "Generate an abstract for a course on space.",
    },
  ],
  model: "gpt-4",
  stream = true,
  stream_options: {
    include_usage: true, // set to true
  },
});

client = OpenAI(
    # ...
    headers={
        "helicone-stream-usage": "true"
    }
)

client.chat.completions.create(
    model="gpt-4",
    messages=[{"role": "user", "content": "Hello!"}],
    stream=True
)

const openai = new OpenAI({
  // ...
  headers: {
    "helicone-stream-usage": "true",
  },
});

openai.chat.completions.create({
  messages: [{ role: "user", content: "Hello!" }],
  model: "gpt-4",
  stream: true,
});