code: def new_address(self, sender=None, nonce=None):
          
          if sender is not None and nonce is None:
              nonce = self.get_nonce(sender)
  
          new_address = self.calculate_new_address(sender, nonce)
          if sender is None and new_address in self:
              return self.new_address(sender, nonce)
          return new_address
docs: Create a fresh 160bit address