Function maybe_emit_entry 

pub(crate) fn maybe_emit_entry(
    provider: &Arc<KafkaProvider>,
    record: Record,
    buffered_records: &mut HashMap<RegionId, Vec<Record>>,
) -> Result<Option<Entry>>

For type of [Entry::Naive] Entry:

• Emits a RecordType::Full type record immediately.

For type of [Entry::MultiplePart] Entry:

• Emits a complete or incomplete [Entry] while the next same [RegionId] record arrives.

Incomplete Entry: If the records arrive in the following order, it emits the incomplete [Entry] when the next record arrives.

• RecordType::First, RecordType::Middle, RecordType::First
• RecordType::Middle, RecordType::First
• RecordType::Last