new_uuid = o.uuid.sub(/..........$/, rand(2**256).to_s(36)[0..9])
assert(!o.update_attributes(uuid: new_uuid),
"should not change uuid of #{ofixt} that owns objects")
new_uuid = o.uuid.sub(/..........$/, rand(2**256).to_s(36)[0..9])
assert(!o.update_attributes(uuid: new_uuid),
"should not change uuid of #{ofixt} that owns objects")