Walter also played for O'Brien during his tenure with the Celtics.

Entity and relation annotations:
id: 0
type: entity
value: text: Walter
labels: <Person>
id: 1
type: entity
value: text: O'Brien
labels: <Organization>
id: 2
type: entity
value: text: the Celtics
labels: <Organization>
type: relation
to_id: 1
labels: Person:affiliated_with:Organization
from_id: 0
type: relation
to_id: 2
labels: Person:affiliated_with:Organization
from_id: 0