code: def install_reactor(explicitReactor=None, verbose=False):
      
      import sys
  
      if explicitReactor:
          ## install explicitly given reactor
          ##
          from twisted.application.reactors import installReactor
          print("Trying to install explicitly specified Twisted reactor '%s'" % explicitReactor)
          try:
              installReactor(explicitReactor)
          except Exception as e:
              print("Could not install Twisted reactor %s%s" % (explicitReactor, ' ["%s"]' % e if verbose else ''))
              sys.exit(1)
      else:
          ## automatically choose optimal reactor
          ##
          if verbose:
              print("Automatically choosing optimal Twisted reactor")
          install_optimal_reactor(verbose)
  
      ## now the reactor is installed, import it
      from twisted.internet import reactor
  
      if verbose:
          from twisted.python.reflect import qual
          print("Running Twisted reactor %s" % qual(reactor.__class__))
  
      return reactor
docs: Install Twisted reactor.
  
      :param explicitReactor: If provided, install this reactor. Else, install optimal reactor.
      :type explicitReactor: obj
      :param verbose: If ``True``, print what happens.
      :type verbose: bool