code: def true_negatives(self, idx):
      return (
          self.all
          - self.sum_predictions[idx]
          - self.sum_conditions[idx]
          + self.true_positives(idx)
      )
  
imports: import logging
  from collections import OrderedDict
  import numpy
  from sklearn import metrics
  from sklearn.metrics import confusion_matrix
label_desc: Use image node_id 4 for calling the ConfusionMatrix obj's underlying member method code with example usage: obj.true_negatives(idx) and returns: unknown