code: def _get_unique(self, *args):
          
  
          # Generate a unique values
          value = ''
          attempts = 0
          while True:
              attempts += 1
              value = self._maker(*args)
              if value not in self._used_values:
                  break
  
              assert attempts < self._max_attempts, \
                  'Too many attempts to generate a unique value'
  
          # Add the value to the set of used values
          self._used_values.add(value)
  
          return value
docs: Generate a unique value using the assigned maker