<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 async def revoke(self, schemaId: ID, i):
 """ Performs revocation of a Claim. :param schemaId: The schema ID (reference to claim definition schema) :param i: claim's sequence number within accumulator """

        acc, ts = await self._nonRevocationIssuer.revoke(schemaId, i)
        await self.wallet.submitAccumUpdate(schemaId=schemaId, accum=acc,
                                            timestampMs=ts)