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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 decode(self, token, verify=True):
 """ Performs a validation of the given token and returns its payload dictionary. Raises a `TokenBackendError` if the token is malformed, if its signature check fails, or if its 'exp' claim indicates it has expired. """

        try:
            return jwt.decode(token, self.verifying_key, algorithms=[self.algorithm], verify=verify)
        except InvalidTokenError:
            raise TokenBackendError(_('Token is invalid or expired'))