@Override
    public TensorFunction<NAMETYPE> withArguments(List<TensorFunction<NAMETYPE>> arguments) {
        if ( arguments.size() != 1)
            throw new IllegalArgumentException("MapSubspaces must have 1 argument, got " + arguments.size());
        return new MapSubspaces<NAMETYPE>(arguments.get(0), function);
    }
The <i>map_subspaces</i> tensor function transforms each dense subspace in a (mixed) tensor

@author arnej
vespajlib/src/main/java/com/yahoo/tensor/functions/MapSubspaces.java