allowDiskUse lets the server know if it can use disk to store temporary results for the aggregation (requires mongodb 2.6 >).allowDiskUse让服务器知道它是否可以使用磁盘存储聚合的临时结果（需要mongodb 2.6>）。
The number of documents to return per batch.每批要返回的文档数。
return BSON regular expressions as BSONRegExp instances.返回BSON正则表达式作为BSONRegExp实例。
Allow driver to bypass schema validation in MongoDB 3.2 or higher.允许驱动程序在MongoDB 3.2或更高版本中绕过模式验证。
the serializer will check if keys are valid.序列化程序将检查键是否有效。
Specify collation.指定排序规则。
Comment to apply to the operation.要应用于操作的注释。
In server versions pre-4.4, 'comment' must be string. 在4.4之前的服务器版本中，“comment”必须是字符串。A server error will be thrown if any other type is provided.如果提供任何其他类型，将引发服务器错误。
In server versions 4.4 and above, 'comment' can be any valid BSON type.在4.4及以上版本的服务器中，“comment”可以是任何有效的BSON类型。
Return the query as cursor, on 2.6 > it returns as a real cursor on pre 2.6 it returns as an emulated cursor.将查询作为游标返回，在2.6>上，它作为实际游标返回到2.6之前的版本，它作为模拟游标返回。
Enable utf8 validation when deserializing BSON documents. 反序列化BSON文档时启用utf8验证。Defaults to true.默认为true。
Specifies the verbosity mode for the explain output.指定解释输出的详细模式。
allow to specify if there what fields we wish to return as unserialized raw buffer.允许指定是否存在我们希望作为非序列化原始缓冲区返回的字段。
Allowed values: 'updateLookup', 'whenAvailable', 'required'.允许的值：“updateLookup”、“whenAvailable”、“required”。
When set to 'updateLookup', the change notification for partial updates will include both a delta describing the changes to the document as well as a copy of the entire document that was changed from some time after the change occurred.当设置为“updateLookup”时，部分更新的更改通知将包括描述文档更改的增量以及更改发生后某个时间更改的整个文档的副本。
When set to 'whenAvailable', configures the change stream to return the post-image of the modified document for replace and update change events if the post-image for this event is available.如果设置为“whenAvailable”，则将更改流配置为返回已修改文档的后期图像以替换和更新更改事件（如果此事件的后期图像可用）。
When set to 'required', the same behavior as 'whenAvailable' except that an error is raised if the post-image is not available.当设置为“required”时，与“whenAvailable”相同的行为，但如果后期图像不可用，则会引发错误。
Allowed values: 'whenAvailable', 'required', 'off'.允许的值：“whenAvailable”、“required”、“off”。
The default is to not send a value, which is equivalent to 'off'.默认值是不发送值，相当于“off”。
When set to 'whenAvailable', configures the change stream to return the pre-image of the modified document for replace, update, and delete change events if it is available.当设置为“whenAvailable”时，将更改流配置为返回修改后的文档的预映像，以便替换、更新和删除更改事件（如果可用）。
When set to 'required', the same behavior as 'whenAvailable' except that an error is raised if the pre-image is not available.当设置为“required”时，与“whenAvailable”相同的行为，但如果预映像不可用，则会引发错误。
Add an index selection hint to an aggregation command向聚合命令添加索引选择提示
serialize will not emit undefined fields (default:true)序列化不会发出未定义的字段（默认值：true）
Map of parameter names and values that can be accessed using $$var (requires MongoDB 5.0).可以使用$$var访问的参数名称和值的映射（需要MongoDB 5.0）。
The maximum amount of time for the server to wait on new documents to satisfy a change stream query.服务器等待新文档以满足更改流查询的最长时间。
specifies a cumulative time limit in milliseconds for processing operations on the cursor. 指定处理游标操作的累积时间限制（毫秒）。MongoDB interrupts the operation at the earliest following interrupt point.MongoDB在最早的中断点中断操作。
when deserializing a Binary will return it as a node.js Buffer instance.当反序列化Binary时，它将作为nodejs Buffer实例返回。
when deserializing a Long will fit it into a Number if it's smaller than 53 bits当反序列化Long时，如果Long小于53位，它将适合Number
when deserializing will promote BSON values to their Node.js closest equivalent types.当反序列化将把BSON值提升到它们的Nodej最接近的等效类型时。
Return BSON filled buffers from operations从操作返回BSON填充的缓冲区
Specify a read concern and level for the collection. (only MongoDB 3.2 or higher supported)指定集合的读取关注点和级别。（仅支持MongoDB 3.2或更高版本）
The preferred read preference (ReadPreference.primary, ReadPreference.primary_preferred, ReadPreference.secondary, ReadPreference.secondary_preferred, ReadPreference.nearest).首选读取首选项（ReadPreference.primary、ReadPreference.primary_preferred、ReadPreference.secondary、ReadPreference.secondary_preferred、ReadPreference.nearest）。
Allows you to start a changeStream after a specified event.允许您在指定事件后启动changeStream。
Should retry failed writes应重试失败的写入
serialize the javascript functions (default:false).序列化javascript函数（默认值：false）。
Specify ClientSession for this command为此命令指定ClientSession
When enabled, configures the change stream to include extra change events.启用后，将更改流配置为包含额外的更改事件。
Similar to resumeAfter, but will allow you to start after an invalidated event.类似于resumeAfter，但将允许您在无效事件后开始。
Will start the changeStream after the specified operationTime.将在指定的operationTime之后启动changeStream。
Write Concern as an object将关注点写为对象
Generated using TypeDoc
Options that can be passed to a ChangeStream.可以传递给ChangeStream的选项。Note that startAfter, resumeAfter, and startAtOperationTime are all mutually exclusive, and the server will error if more than one is specified.请注意，startAfter、resumeAfter和startAtOperationTime都是互斥的，如果指定了多个，服务器将出错。