code: def reassign(self, from_email, user_ids):
          
          endpoint = '/'.join((self.endpoint, self.id,))
  
          if from_email is None or not isinstance(from_email, six.string_types):
              raise MissingFromEmail(from_email)
  
          if user_ids is None or not isinstance(user_ids, list):
              raise InvalidArguments(user_ids)
          if not all([isinstance(i, six.string_types) for i in user_ids]):
              raise InvalidArguments(user_ids)
  
          assignees = [
              {
                  'assignee': {
                      'id': user_id,
                      'type': 'user_reference',
                  }
              }
              for user_id in user_ids
          ]
  
          add_headers = {'from': from_email, }
          data = {
              'incident': {
                  'type': 'incident',
                  'assignments': assignees,
              }
          }
  
          result = self.request('PUT',
                                endpoint=endpoint,
                                add_headers=add_headers,
                                data=data,)
          return result
docs: Reassign an incident to other users using a valid email address.