This was missing from the pacbio branch, and it makes getting the input
sample of a PCR product in ViroDB-world not work correctly because
Extraction instances have a sample_id method, but it returns the actual
numeric ID, not a reference to a sample as in CDBI-world.
This was missing from the pacbio branch, and it makes getting the input sample of a PCR product in ViroDB-world not work correctly because Extraction instances have a sample_id method, but it returns the actual numeric ID, not a reference to a sample as in CDBI-world.