The client's view of a single server, based on the most recent hello outcome.
Internal type, not meant to be directly instantiated
可选
Is this server data bearing
Is this server available for reads
Is this server available for writes
Determines if another ServerDescription is equal to this one per the rules defined in the spec
ServerDescription
The client's view of a single server, based on the most recent hello outcome.
Internal type, not meant to be directly instantiated