dist/extensions/snapshots.js
function rollback(numVersions) {
            var snapshotsLength = this.$$snapshots ? this.$$snapshots.length : 0;
            numVersions = Math.min(numVersions || 1, snapshotsLength);

            if (numVersions < 0) {
                numVersions = snapshotsLength;
            }

            if (snapshotsLength) {
                this.rollbackTo(this.$$snapshots.length - numVersions);
            }

            return true;
        }
function rollback(numVersions) {
            var snapshotsLength = this.$$snapshots ? this.$$snapshots.length : 0;
            numVersions = Math.min(numVersions || 1, snapshotsLength);

            if (numVersions < 0) {
                numVersions = snapshotsLength;
            }

            if (snapshotsLength) {
                this.rollbackTo(this.$$snapshots.length - numVersions);
            }

            return true;
        }
function rollback ( numVersions ) { var snapshotsLength = this . $$snapshots ? this . $$snapshots . length : 0 ; numVersions = Math . min ( numVersions || 1 , snapshotsLength ) ; if ( numVersions < 0 ) { numVersions = snapshotsLength ; } if ( snapshotsLength ) { this . rollbackTo ( this . $$snapshots . length - numVersions ) ; } return true ; }
Rolls back the resource to a previous snapshot.

When numVersions is undefined or 0 then a single version is rolled back.
When numVersions exceeds the stored number of snapshots then the resource is rolled back to the first snapshot version.
When numVersions is less than 0 then the resource is rolled back to the first snapshot version.

@param {Number|undefined} numVersions The number of versions to roll back to.  If undefined then
@returns {Boolean} true if rollback was successful, false otherwise
Rolls back the resource to a previous snapshot .