Implement a method on the collection object, `syncIndexes`, that takes a list of IndexModels (similar to the existing `createIndexes` method) and ensures that the indexes in the collection is exactly the same as those specified in the list. Similar features already exist in Mongoose: https://mongoosejs.com/docs/api/model.html#Model.syncIndexes(). Why this should be in the library: It is incredibly difficult and error prone to implement this manually (which is what we're doing right now): * We currently do this along with some other Mongo sanity checks when our server starts up. Since this requires multiple `createIndexes`, `getIndexes`, and `dropIndexes` calls, and to ensure isolation we use a distributed lock to ensure only one server is doing this at the same time. If this is implemented natively in Mongo or the driver as a one-shot operation, this lock wouldn't be needed. * There are some particular nasty ordering issues. For instance, on a sharded collection, if an index exists in the DB as the shard key, and in our code we want to add a new property to the index (say making it unique), we would need to 1. Create a new dummy index which is {"shard_key": ..., "dummy_key": 1}. 2. Delete the existing index. 3. Recreate the index with the property set to what we want. 4. Delete the dummy index. Again, if this is a native API, developers wouldn't need to think about these issues.