fn construct_source_message(
msg: &BorrowedMessage<'_>,
metadata_columns: &[KafkaMetadataKind],
) -> (Result<SourceMessage, KafkaHeaderParseError>, (PartitionId, MzOffset))
fn construct_source_message(
msg: &BorrowedMessage<'_>,
metadata_columns: &[KafkaMetadataKind],
) -> (Result<SourceMessage, KafkaHeaderParseError>, (PartitionId, MzOffset))