message: Check for undefined options
diff: @@ -909,7 +909,7 @@ export class Client {
  // TODO: Remove options flag once new snapshot format is adopted as default.
  // (See https://github.com/microsoft/FluidFramework/issues/84)
  - const snap = this.mergeTree.options.newMergeTreeSnapshotFormat
  + const snap = this.mergeTree.options && this.mergeTree.options.newMergeTreeSnapshotFormat
  ? new Snapshot(this.mergeTree, this.logger)
  : new SnapshotLegacy(this.mergeTree, this.logger);
  