code: def _default(self):
          
          try:
              # Check if it's iterable
              iter(self.default)
          except TypeError:
              return repr(self.default)
  
          # This is to look for unparsable values, and if we find one, we try to
          # directly parse the string
          for v in self.default:
              if isinstance(v, Unparseable):
                  default = self._default_value_only()
                  if default:
                      return default
          # Otherwise just make it a string and go
          return ', '.join(str(v) for v in self.default)
docs: Return the default argument, formatted nicely.