code: @SuppressWarnings("unchecked")
    public static <V extends NumberVector, T extends NumberVector> Relation<V> relationUglyVectorCast(Relation<T> database) {
      return (Relation<V>) database;
    }
docs: An ugly vector type cast unavoidable in some situations due to Generics.
  
  @param <V> Base vector type
  @param <T> Derived vector type (is actually V, too)
  @param database Database
  @return Database