title: Python: keep open browser in pyppeteer and create CDPSession
body: <p>I've got two issues that I can't solve it at them moment.</p>
  
  <p><strong>1.</strong> I would like to keep the browser running so I could just re-connect using <a href="https://miyakogi.github.io/pyppeteer/reference.html#pyppeteer.launcher.connect" rel="noreferrer"><code>pyppeteer.launcher.connect()</code></a> function but it seems to be closed imidiately even if I don't call <a href="https://miyakogi.github.io/pyppeteer/reference.html#pyppeteer.browser.Browser.close" rel="noreferrer"><code>pyppeteer.browser.Browser.close()</code></a>.</p>
  
  <p><strong>test01.py:</strong></p>
  
  <pre><code>import asyncio
  
  from pyppeteer import launch, connect
  
  async def fetch():
      browser = await launch(
          headless=False,
          args=['--no-sandbox']
      )
      print(f'Endpoint: {browser.wsEndpoint}')
      await browser.disconnect()
  
  loop = asyncio.get_event_loop()
  loop.run_until_complete(fetch())
  
  $ python test01.py
  Endpoint: ws://127.0.0.1:51757/devtools/browser/00e917a9-c031-499a-a8ee-ca4090ebd3fe
  $ curl -i -N -H "Connection: Upgrade" -H "Upgrade: websocket" http://127.0.0.1:51757
  curl: (7) Failed to connect to 127.0.0.1 port 51757: Connection refused
  </code></pre>
  
  <p><strong>2.</strong> How do I create CDP session. This code should open another browser window but it doesn't work as expected:</p>
  
  <p><strong>test02.py</strong></p>
  
  <pre><code>import asyncio
  import time
  
  from pyppeteer import launch, connect
  
  async def fetch():
      browser = await launch(
          headless=False,
          args=['--no-sandbox']
      )
      page = await browser.newPage()
      cdp = await page.target.createCDPSession()
      await cdp.send('Target.createBrowserContext')
      time.sleep(5)
      await browser.disconnect()
  
  loop = asyncio.get_event_loop()
  loop.run_until_complete(fetch())
  
  $ python test02.py
  Future exception was never retrieved
  future: &lt;Future finished exception=NetworkError('Protocol error Target.sendMessageToTarget: Target closed.',)&gt;
  pyppeteer.errors.NetworkError: Protocol error Target.sendMessageToTarget: Target closed.
  </code></pre>