class DimensionUserDetail implements Serializable {
    private static final long serialVersionUID = -6849794470754667710L;


    private String userId;

    private List<Dimension> dimensions;

    public DimensionUserDetail merge(DimensionUserDetail detail) {<FILL_FUNCTION_BODY>}
}

        DimensionUserDetail newDetail = new DimensionUserDetail();
        newDetail.setUserId(userId);
        newDetail.setDimensions(new ArrayList<>());
        if (null != dimensions) {
            newDetail.dimensions.addAll(dimensions);
        }
        if (null != detail.getDimensions()) {
            newDetail.dimensions.addAll(detail.getDimensions());
        }
        return newDetail;
    
<no_super_class>