code: def login(self, login=None, password=None):
          
  
          if (login is not None) and (password is not None):
              login_data = {'user': login, 'pass': password}
          elif (self.default_login is not None) and (self.default_password is not None):
              login_data = {'user': self.default_login, 'pass': self.default_password}
          elif self.session.auth:
              login_data = None
          else:
              raise AuthorizationError('Credentials required, fill login and password.')
          try:
              self.login_result = self.__get_status_code(self.__request('',
                                                                        post_data=login_data,
                                                                        without_login=True)) == 200
          except AuthorizationError:
              # This happens when HTTP Basic or Digest authentication fails, but
              # we will not raise the error but just return False to indicate
              # invalid credentials
              return False
          return self.login_result
docs: Login with default or supplied credetials.
  
          .. note::
  
              Calling this method is not necessary when HTTP basic or HTTP
              digest_auth authentication is used and RT accepts it as external
              authentication method, because the login in this case is done
              transparently by requests module. Anyway this method can be useful
              to check whether given credentials are valid or not.
  
          :keyword login: Username used for RT, if not supplied together with
                          *password* :py:attr:`~Rt.default_login` and
                          :py:attr:`~Rt.default_password` are used instead
          :keyword password: Similarly as *login*
  
          :returns: ``True``
                        Successful login
                    ``False``
                        Otherwise
          :raises AuthorizationError: In case that credentials are not supplied neither
                                      during inicialization or call of this method.