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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def encode(self, sequence):
 """ Encodes a ``sequence``. Args: sequence (str):
 String ``sequence`` to encode. Returns: torch.Tensor: Encoding of the ``sequence``. """

        sequence = super().encode(sequence)
        sequence = self.tokenize(sequence)
        vector = [self.stoi.get(token, self.unknown_index) for token in sequence]
        if self.append_eos:
            vector.append(self.eos_index)
        return torch.tensor(vector)