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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 parse(self):
 """Parse and return an nbt literal from the token stream."""

        token_type = self.current_token.type.lower()
        handler = getattr(self, f'parse_{token_type}', None)
        if handler is None:
            raise self.error(f'Invalid literal {self.current_token.value!r}')
        return handler()