MongoCollection to Java List

Question

I have a Java object that looks like this:

public class Partner {
    private String partnerName;
    private String partnerRef;
    private Site sites;

I have this stored in MongoDB as a document. I am attempting to retrieve it like this:

    public List<Partner> getAllPartners(
            MongoCollection<Partner> partnerCollection) {
        List<Partner> partnerList = new ArrayList<>();
        return partnerCollection.find().into(partnerList);
    }

I keep receiving the below error:

"message": "An exception occurred when decoding using the AutomaticPojoCodec.\nDecoding into a 'Partner' failed with the following exception:\n\nFailed to decode 'Partner'. Decoding 'sites' errored with: readStartDocument can only be called when CurrentBSONType is DOCUMENT, not when CurrentBSONType is ARRAY.\n\nA custom Codec or PojoCodec may need to be explicitly configured and registered to handle this type.",

I assume this is occurring because of the Site object within the Partner Object, but I cannot for the life of me figure out how to fix this problem.