text: from abc import ABC
  from typing import Any
  from typing import Optional
  
  from amp.models import model
  
  
  class Discriminator(model.Model, ABC):
      """ Perform classification on a sequence."""
  
      def output_tensor(self, input_: Optional[Any] = None):
          raise NotImplementedError
  
      def output_tensor_with_dense_input(self, input_: Optional[Any] = None):
          raise NotImplementedError
  
      def __call__(self, input_: Optional[Any] = None):
          raise NotImplementedError
  
      def freeze_layers(self):
          raise NotImplementedError
  
      def unfreeze_layers(self):
          raise NotImplementedError
  
      def train_for_n_epochs_with_batch_size(self, epochs: int, batch_size: int, **kwargs):
          raise NotImplementedError
  