def _configuration(self, kwargs, config_item):
if '<STR_LIT>' not in config_item:<EOL><INDENT>if '<STR_LIT>' not in kwargs:<EOL><INDENT>return<EOL><DEDENT>nc = kwargs['<STR_LIT>'] = {}<EOL>for field in Resource.configuration[kwargs['<STR_LIT>']]:<EOL><INDENT>if field not in config_item:<EOL><INDENT>raise exc.TowerCLIError('<STR_LIT>'<EOL>'<STR_LIT>' % field)<EOL><DEDENT>else:<EOL><INDENT>nc[field] = config_item[field]<EOL><DEDENT><DEDENT><DEDENT>else:<EOL><INDENT>kwargs['<STR_LIT>'] =config_item['<STR_LIT>']<EOL><DEDENT>
Combine configuration-related keyworded arguments into
        notification_configuration.