PlainTable with prefix_extractor do not support manual compaction?

use plaintable format with prefix_extractor & hash_table_ratio.
write data to db.
And I called CompactRange，but got a failed status:Invalid argument: total_order_seek not implemented for PlainTable.

why CompactRange should call PlainTableIterator::Seek method?
if it`s needed ,then why plaintable format don`t support Seek?

Thanks!
### Expected behavior

use plaintable format with prefix_extractor & hash_table_ratio.
CompactRange succeed.

### Actual behavior

got a failed status:Invalid argument: total_order_seek not implemented for PlainTable.

### Steps to reproduce the behavior
use plaintable format with prefix_extractor & hash_table_ratio.
write data to db, create 2 or more sst files.
called CompactRange (x, x , null, null);