docs: def search_assignable_users_for_projects(self, username, projectKeys, startAt=0, maxResults=50):
          """Get a list of user Resources that match the search string and can be assigned issues for projects.
  
          :param username: A string to match usernames against
          :type username: str
          :param projectKeys: Comma-separated list of project keys to check for issue assignment permissions
          :type projectKeys: str
          :param startAt: Index of the first user to return (Default: 0)
          :type startAt: int
          :param maxResults: Maximum number of users to return.
                  If maxResults evaluates as False, it will try to get all users in batches. (Default: 50)
          :type maxResults: int
  
          :rtype: ResultList
  
          """
          params = {
              'username': username,
              'projectKeys': projectKeys}
          return self._fetch_pages(User, None, 'user/assignable/multiProjectSearch', startAt, maxResults, params)