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 [Entry] immediately when a RecordType::Last record arrives with buffered parts.
• Emits an incomplete [Entry] when a new RecordType::First record replaces buffered incomplete records for the same [RegionId].

Discarded records:

• A standalone RecordType::First record is discarded when another RecordType::First record with the same payload for the same [RegionId] arrives.
• A RecordType::Last record without buffered parts is discarded.

A trailing incomplete entry is emitted by remaining_entries.