Do some pre-run cleanup that is usually performed in Task __init__.

def runtime_cleanup(self, selected_uids):
        """Do some pre-run cleanup that is usually performed in Task __init__.
        """
        self.run_count = 0
        self.num_nodes = len(selected_uids)
        self.node_results = []
        self._skipped_children = {}
        self._skipped_children = {}
        self._raise_next_tick = None