# The following lines are equivalent:
      ds = datasets.load_dataset('mnist', split='test[:33%](pct1_dropremainder)')
      ds = datasets.load_dataset('mnist', split=datasets.ReadInstruction.from_spec(
          'test[:33%](pct1_dropremainder)'))
      ds = datasets.load_dataset('mnist', split=datasets.ReadInstruction(
          'test', from_=0, to=33, unit='%', rounding="pct1_dropremainder"))

      # 10-fold validation:
      tests = datasets.load_dataset(
          'mnist',
          [datasets.ReadInstruction('train', from_=k, to=k+10, unit='%')
          for k in range(0, 100, 10)])
      trains = datasets.load_dataset(
          'mnist',
          [datasets.ReadInstruction('train', to=k, unit='%') + datasets.ReadInstruction('train', from_=k+10, unit='%')
          for k in range(0, 100, 10)])

    """

    def _init(self, relative_instructions):
        # Private initializer.
        self._relative_instructions = relative_instructions