code: async def verify(self, message: bytes, signature: bytes, signer: str = None) -> bool:
          
  
          LOGGER.debug('BaseAnchor.verify >>> signer: %s, message: %s, signature: %s', signer, message, signature)
  
          if not self.wallet.handle:
              LOGGER.debug('BaseAnchor.verify <!< Wallet %s is closed', self.name)
              raise WalletState('Wallet {} is closed'.format(self.name))
  
          verkey = None
          if signer:
              verkey = await self._verkey_for(signer)
          rv = await self.wallet.verify(message, signature, verkey)
  
          LOGGER.debug('BaseAnchor.verify <<< %s', rv)
          return rv
docs: Verify signature with input signer verification key (via lookup by DID first if need be).
          Raise WalletState if wallet is closed.
  
          :param message: Content to sign, as bytes
          :param signature: signature, as bytes
          :param signer: signer DID or verification key; omit for anchor's own
          :return: whether signature is valid