code: def parse_parameter_group(self, global_params, region, parameter_group):
          
          pg_name = parameter_group.pop('ParameterGroupName')
          pg_id = self.get_non_aws_id(pg_name) # Name could be used as only letters digits or hyphens
          parameter_group['name'] = pg_name
          parameter_group['parameters'] = {}
          api_client = api_clients[region]
          parameters = handle_truncated_response(api_client.describe_cluster_parameters, {'ParameterGroupName': pg_name}, ['Parameters'])['Parameters']
          for parameter in parameters:
              param = {}
              param['value'] = parameter['ParameterValue']
              param['source'] = parameter['Source']
              parameter_group['parameters'][parameter['ParameterName']] = param
          (self).parameter_groups[pg_id] = parameter_group
docs: Parse a single Redshift parameter group and fetch all of its parameters
  
          :param global_params:           Parameters shared for all regions
          :param region:                  Name of the AWS region
          :param parameter_group:         Parameter group