code: def f1_score(self, idx):
      return self.fbeta_score(1, 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 19 for calling the ConfusionMatrix obj's underlying member method code with example usage: obj.f1_score(idx) and returns: self