class_docstr: Checks that all sub-markers applied at least once in history.
  
  It doesn't matter if the sub markers stop applying later in history. If they
  applied at least once they will always evaluate to `True`.
class_docstr_tok: ["Checks","that","all","sub-markers","applied","at","least","once","in","history",".","It","does","n't","matter","if","the","sub","markers","stop","applying","later","in","history",".","If","they","applied","at","least","once","they","will","always","evaluate","to","`","True","`","."]
code: def _non_negated_version_applies_at(self, event: Event) -> bool:
      occurred_before = False
  
      if self.history:
          occurred_before = self.history[-1]
          if self.negated:
              occurred_before = not occurred_before
  
      return occurred_before or 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 4 for calling the OccurrenceMarker obj's underlying member method code with example usage: obj._non_negated_version_applies_at(event) and returns: unknown