code: def get_auth_instance(credentials, auth_type):
      
      model = AUTH_TYPE_MAP[auth_type]
      if model is None:
          return None
      username = credentials.username
      if auth_type == NTLM and credentials.type == credentials.EMAIL:
          username = '\\' + username
      if auth_type == GSSAPI:
          # Kerberos auth relies on credentials supplied via a ticket available externally to this library
          return model()
      return model(username=username, password=credentials.password)
docs: Returns an *Auth instance suitable for the requests package