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)