class_docstr: Checks that at least one sub-marker applies.
class_docstr_tok: ["Checks","that","at","least","one","sub-marker","applies","."]
code: def _non_negated_version_applies_at(self, event: Event) -> bool:
      return not self.sub_markers[0].history[-1]
  
imports: from rasa.shared.core.domain import Domain
  from typing import Optional, Text, List
  from rasa.core.evaluation.marker_base import OperatorMarker, ConditionMarker, MarkerRegistry, Marker
  from rasa.shared.core.events import ActionExecuted, SlotSet, UserUttered, Event
  import logging
label_desc: Use image node_id 3 for calling the NotMarker obj's underlying member method code with example usage: obj._non_negated_version_applies_at(event) and returns: unknown