old_contents: 
  from urllib3.connection import HTTPConnection, HTTPSConnection
  from urllib3.connectionpool import HTTPConnectionPool, HTTPSConnectionPool
  
  
  def _output(self, s):
      """Host header should always be first"""
  
      if s.lower().startswith('host: '):
          self._buffer.insert(1, s)
      else:
          self._buffer.append(s)
  
  HTTPConnectionPool.ConnectionCls = type(
      'RevProxyHTTPConnection',
      (HTTPConnection,),
      {'_output': _output},
  )
  
  HTTPSConnectionPool.ConnectionCls = type(
      'RevProxyHTTPSConnection',
      (HTTPSConnection,),
      {'_output': _output}
  )
  
new_contents: 
  from urllib3.connection import HTTPConnection, HTTPSConnection
  from urllib3.connectionpool import HTTPConnectionPool, HTTPSConnectionPool
  
  
  def _output(self, s):
      """Host header should always be first"""
  
      if s.lower().startswith(b'host: '):
          self._buffer.insert(1, s)
      else:
          self._buffer.append(s)
  
  HTTPConnectionPool.ConnectionCls = type(
      'RevProxyHTTPConnection',
      (HTTPConnection,),
      {'_output': _output},
  )
  
  HTTPSConnectionPool.ConnectionCls = type(
      'RevProxyHTTPSConnection',
      (HTTPSConnection,),
      {'_output': _output}
  )
  
subject: Fix byte string bug