<s> import uuid <EOL> from oslo_middleware import base <EOL> class CorrelationId ( base . ConfigurableMiddleware ) : <EOL> "<STR_LIT>" <EOL> def process_request ( self , req ) : <EOL> correlation_id = ( req . headers . get ( "<STR_LIT>" ) or <EOL> str ( uuid . uuid4 ( ) ) ) <EOL> req . headers [ '<STR_LIT>' ] = correlation_id </s>
