code: def class_one_c(prediction, y, significance):
      """Calculates the rate of singleton predictions (prediction sets containing
      only a single class label) of a conformal classification model.
      """
      prediction = prediction > significance
      n_singletons = np.sum(
          1 for _ in filter(lambda x: np.sum(x) == 1, prediction)
      )
      return n_singletons / y.size
  
file_path: lightwood/lightwood/analysis/nc/metrics.py
imports: import numpy
label_desc: Use image node_id 17 for calling a global function with example usage: class_one_c(prediction, y, significance) and returns: unknown