code: def get_fas(config):
      
      global _FAS
      if _FAS is not None:
          return _FAS
  
      # In some development environments, having fas_credentials around is a
      # pain.. so, let things proceed here, but emit a warning.
      try:
          creds = config['fas_credentials']
      except KeyError:
          log.warn("No fas_credentials available.  Unable to query FAS.")
          return None
  
      default_url = 'https://admin.fedoraproject.org/accounts/'
  
      _FAS = AccountSystem(
          creds.get('base_url', default_url),
          username=creds['username'],
          password=creds['password'],
          cache_session=False,
          insecure=creds.get('insecure', False)
      )
  
      return _FAS
docs: Return a fedora.client.fas2.AccountSystem object if the provided
      configuration contains a FAS username and password.