code: def TNE_metric(bpmn_graph):
      
  
      events_counts = get_events_counts(bpmn_graph)
  
      return sum(
          [count for _, count in events_counts.items()]
      )
docs: Returns the value of the TNE metric (Total Number of Events of the Model)
      for the BPMNDiagramGraph instance.
  
      :param bpmn_graph: an instance of BpmnDiagramGraph representing BPMN model.