Firebase Database Transaction MutableData for ArrayList

Question

Currently trying to get an ArrayList of a Java Object from the MutableData in a Firebase Realtime Database. However, I am receiving null and I'm unsure on if I am passing the class argument properly. I'm currently using the class argument as ArrayList.class but I don't think it will be able to handle the custom java objects within it.

  public Transaction.Result doTransaction(MutableData mutableData) {
            ArrayList<Friend> friends = mutableData.getValue(ArrayList.class);
            if (friends != null) {
                User.getInstance().setFriendList(friends);
                return Transaction.success(mutableData);
            } else {
                Log.e("DAO", "Failed to load user friends list.");
                User.getInstance().setFriendList(new ArrayList<>());
                return Transaction.abort();
            }

        }

This is the Friend pojo:

public class Friend {

public Friend(String displayName, String uid){
    this.name = displayName;
    this.uid = uid;
}

private String name;

public String getUID() {
    return uid;
}

public void setUID(String uid) {
    this.uid = uid;
}

private String uid;

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

}