code: def label_to_idx(self, label):
      return self.label2idx[label]
  
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 2 for calling the ConfusionMatrix obj's underlying member method code with example usage: obj.label_to_idx(label) and returns: self