@staticmethod
def tree_transitions_from_inactive_to_unsure_and_best_upstream_is_not_null(
    interface: 'TreeInterfaceDownstream'):
    """
        Tree transitions from Inactive to Unsure state AND
        BestUpstream neighbor is not null
        """
    interface.logger.debug(
        'tree_transitions_from_inactive_to_unsure_and_best_upstream_is_not_null'
        )
    interface.send_no_interest()
