docs(ChangeStream): fix name of stream changes watch option startAtOp…

…erationTime

- it was changed during alpha, beta testing from startAtClusterTime to startAtOperationTime,
but JSDocs keeps old option name.
- related to api ref docs: https://mongodb.github.io/mongo-java-driver/3.8/javadoc/com/mongodb/client/ChangeStreamIterable.html
- related to specs: https://github.com/mongodb/specifications/blob/master/source/change-streams/change-streams.rst

lib/collection.js

@@ -1740,7 +1740,7 @@ Collection.prototype.aggregate = function(pipeline, options, callback) {
  * @param {number} [options.batchSize] The number of documents to return per batch. See {@link https://docs.mongodb.com/manual/reference/command/aggregate|aggregation documentation}.
  * @param {object} [options.collation] Specify collation settings for operation. See {@link https://docs.mongodb.com/manual/reference/command/aggregate|aggregation documentation}.
  * @param {ReadPreference} [options.readPreference] The read preference. Defaults to the read preference of the database or collection. See {@link https://docs.mongodb.com/manual/reference/read-preference|read preference documentation}.
- * @param {Timestamp} [options.startAtClusterTime] receive change events that occur after the specified timestamp
+ * @param {Timestamp} [options.startAtOperationTime] receive change events that occur after the specified timestamp
  * @param {ClientSession} [options.session] optional session to use for this operation
  * @return {ChangeStream} a ChangeStream instance.
  */

lib/db.js

@@ -988,7 +988,7 @@ Db.prototype.unref = function() {
  * @param {number} [options.batchSize] The number of documents to return per batch. See {@link https://docs.mongodb.com/manual/reference/command/aggregate|aggregation documentation}.
  * @param {object} [options.collation] Specify collation settings for operation. See {@link https://docs.mongodb.com/manual/reference/command/aggregate|aggregation documentation}.
  * @param {ReadPreference} [options.readPreference] The read preference. Defaults to the read preference of the database. See {@link https://docs.mongodb.com/manual/reference/read-preference|read preference documentation}.
- * @param {Timestamp} [options.startAtClusterTime] receive change events that occur after the specified timestamp
+ * @param {Timestamp} [options.startAtOperationTime] receive change events that occur after the specified timestamp
  * @param {ClientSession} [options.session] optional session to use for this operation
  * @return {ChangeStream} a ChangeStream instance.
  */

lib/mongo_client.js

@@ -420,7 +420,7 @@ MongoClient.prototype.withSession = function(options, operation) {
  * @param {number} [options.batchSize] The number of documents to return per batch. See {@link https://docs.mongodb.com/manual/reference/command/aggregate|aggregation documentation}.
  * @param {object} [options.collation] Specify collation settings for operation. See {@link https://docs.mongodb.com/manual/reference/command/aggregate|aggregation documentation}.
  * @param {ReadPreference} [options.readPreference] The read preference. See {@link https://docs.mongodb.com/manual/reference/read-preference|read preference documentation}.
- * @param {Timestamp} [options.startAtClusterTime] receive change events that occur after the specified timestamp
+ * @param {Timestamp} [options.startAtOperationTime] receive change events that occur after the specified timestamp
  * @param {ClientSession} [options.session] optional session to use for this operation
  * @return {ChangeStream} a ChangeStream instance.
  */