driver-core/src/main/com/mongodb/internal/connection/RequestMessage.java
protected void addCollectibleDocument(final BsonDocument document, final BsonOutput bsonOutput, final FieldNameValidator validator) {
        addDocument(document, getCodec(document), EncoderContext.builder().isEncodingCollectibleDocument(true).build(), bsonOutput,
                    validator, settings.getMaxDocumentSize(), null);
    }
protected void addCollectibleDocument(final BsonDocument document, final BsonOutput bsonOutput, final FieldNameValidator validator) {
        addDocument(document, getCodec(document), EncoderContext.builder().isEncodingCollectibleDocument(true).build(), bsonOutput,
                    validator, settings.getMaxDocumentSize(), null);
    }
Appends a document to the message that is intended for storage in a collection.

@param document the document
@param bsonOutput the output
@param validator the field name validator