Customers have requested the ability to integrate client side field level encryption writing data from Kafka to MongoDB encrypted.  While adding CSFLE specifically to a server component such as Kafka Connect would undermine of the key benefits of CCSFLE namely protection from administrators, the end goal of encrypting one or more fields can be accomplished using a custom write strategy.  This ticket is to create the sample code which will the be used as part of a documentation entry on encrypting fields when using the sink.