Specifies the reason that the user session was assigned this variation. Possible values
include DEFAULT, meaning the user was served the default variation;
LAUNCH_RULE_MATCH, if the user session was enrolled in a launch;
EXPERIMENT_RULE_MATCH, if the user session was enrolled in an experiment; or
ENTITY_OVERRIDES_MATCH, if the user's entityId matches an override
rule.
The value assigned to this variation to differentiate it from the other variations of this feature.
The name of the variation that was served to the user session.
If this user was assigned to a launch or experiment, this field lists the launch or experiment name.