text: from spec.explainers.explainer import Explainer
  
  
  class PrototypeExplainer(Explainer):
  
      def __init__(self, fields_tuples, options):
          super().__init__(fields_tuples)
          pass
  
      def build_loss(self, loss_weights=None):
          self._loss = None
  
      def forward(self, batch, classifier):
          pass
  