Oaklib annotate function does not return all substring containing values as expected

[bsantan]

Example: "runoak -i sqlite:obo:chebi annotate “butyrate”" should have returned all strings that contain butyrate, but, butyr, etc but only returns "butyrate" and "b" containing results.

result:
predicate_id: rdfs:label
object_id: CHEBI:17968
object_label: butyrate
match_string: butyrate
matches_whole_text: false
subject_start: 2
subject_end: 9

---

predicate_id: oio:hasExactSynonym
object_id: CHEBI:17968
object_label: butyrate
match_string: butyrate
matches_whole_text: false
subject_start: 2
subject_end: 9

---

predicate_id: oio:hasRelatedSynonym
object_id: CHEBI:27560
object_label: B
match_string: b
matches_whole_text: false
subject_start: 2
subject_end: 2

---

predicate_id: oio:hasRelatedSynonym
object_id: CHEBI:36370
object_label: b
match_string: b
matches_whole_text: false
subject_start: 2
subject_end: 2

---

predicate_id: oio:hasRelatedSynonym
object_id: CHEBI:41264
object_label: Bu
match_string: bu
matches_whole_text: false
subject_start: 2
subject_end: 3