code: def _format_param_val(self, param_val):
          
          if isinstance(param_val, list):
              return ' '.join(str(x) for x in param_val)
          else:
              return str(param_val)
docs: Internal method to format values in the packmol parameter dictionaries
  
          Args:
                param_val:
                     Some object to turn into String
  
          Returns:
                 string representation of the object