@Nullable
    public static <T> T coalesce(T... args) {
        for (T arg : args) {
            if (arg != null) {
                return arg;
            }
        }
        return null;
    }
{@code CollQueryFunctions} defines function implementation for use in ColQueryTemplates

@author tiwe
querydsl-collections/src/main/java/com/querydsl/collections/CollQueryFunctions.java