code: def token(self, token_address: Address) -> Token:
          
          if not is_binary_address(token_address):
              raise ValueError('token_address must be a valid address')
  
          with self._token_creation_lock:
              if token_address not in self.address_to_token:
                  self.address_to_token[token_address] = Token(
                      jsonrpc_client=self.client,
                      token_address=token_address,
                      contract_manager=self.contract_manager,
                  )
  
          return self.address_to_token[token_address]
docs: Return a proxy to interact with a token.