docs: def register_token(self, *args, **kwargs):
          """
          Register token
  
          Accepts:
              - token_name [string]
              - contract_address [hex string]
              - blockchain [string]  token's blockchain (QTUMTEST, ETH)
          Returns dictionary with following fields:
              - success [Bool]
           """
          client = HTTPClient(self.withdraw_server_address + self.withdraw_endpoint)
          if check_sig:
              return client.request('register_token', self.signature_validator.sign(kwargs))
          else:
              return client.request('register_token', kwargs)