code: def true_negative_rate(
      test=None,
      reference=None,
      confusion_matrix=None,
      nan_for_nonexisting=True,
      **kwargs,
  ):
      return specificity(
          test, reference, confusion_matrix, nan_for_nonexisting
      )
  
imports: import numpy
  from medpy import metric
label_desc: Use image node_id 13 for calling a global function with example usage: true_negative_rate(test, reference, confusion_matrix, nan_for_nonexisting) and returns: specificity