driver-legacy/src/main/com/mongodb/ReplicaSetStatus.java
@SuppressWarnings("deprecation")
    public int getMaxBsonObjectSize() {
        List<ServerDescription> primaries = getClusterDescription().getPrimaries();
        return primaries.isEmpty() ? ServerDescription.getDefaultMaxDocumentSize() : primaries.get(0).getMaxDocumentSize();
    }
@SuppressWarnings("deprecation")
    public int getMaxBsonObjectSize() {
        List<ServerDescription> primaries = getClusterDescription().getPrimaries();
        return primaries.isEmpty() ? ServerDescription.getDefaultMaxDocumentSize() : primaries.get(0).getMaxDocumentSize();
    }
Gets the maximum size for a BSON object supported by the current master server. Note that this value may change over time depending
on which server is master.

@return the maximum size, or 0 if not obtained from servers yet.
@throws MongoException if there's a failure