old_contents: """
  Base interfaces for use in the package.
  The package works according to the interfaces defined below.
  """
  
  from abc import ABCMeta, abstractmethod
  
  
  class QueryStrategy(metaclass=ABCMeta):
      #TODO: documentation
  
      @abstractmethod
      def make_query(self, dataset, n_queries = 1):
          pass
  
  
  class Labeler(metaclass=ABCMeta):
      #TODO: documentation
  
      @abstractmethod
      def label(self, feature):
          pass
  
  
  class Model(metaclass=ABCMeta):
      #TODO: documentation
  
      @abstractmethod
      def fit(self, dataset, *args, **kwargs):
          pass
  
      @abstractmethod
      def predict(self, feature, *args, **kwargs):
          pass
  
      @abstractmethod
      def score(self, testing_dataset, *args, **kwargs):
          pass
  
new_contents: """
  Base interfaces for use in the package.
  The package works according to the interfaces defined below.
  """
  
  from abc import ABCMeta, abstractmethod
  
  
  class QueryStrategy(metaclass=ABCMeta):
      #TODO: documentation
  
      @abstractmethod
      def make_query(self, dataset, n_queries=1):
          pass
  
  
  class Labeler(metaclass=ABCMeta):
      #TODO: documentation
  
      @abstractmethod
      def label(self, feature):
          pass
  
  
  class Model(metaclass=ABCMeta):
      #TODO: documentation
  
      @abstractmethod
      def fit(self, dataset, *args, **kwargs):
          pass
  
      @abstractmethod
      def predict(self, feature, *args, **kwargs):
          pass
  
      @abstractmethod
      def score(self, testing_dataset, *args, **kwargs):
          pass
  
subject: fix coding styles