If you use this approach, an empty Array will be returned when the collection is empty (i.e. when there are no Posts). If you still want to respond with Collection+JSON in this scenario, you can ...
" pm.expect(comment).to.have.property(\"postId\");", " pm.expect(comment).to.have.property(\"name\");", " pm.expect(comment).to.have.property(\"email\");", " pm ...