docs: public Planar<T> partialSpectrum(int ...which ) {
  		Planar<T> out = new Planar<>(getBandType(), which.length);
  
  		out.setWidth(width);
  		out.setHeight(height);
  		out.setStride(stride);
  
  		for (int i = 0; i < which.length; i++) {
  			out.setBand(i,getBand(which[i]));
  		}
  
  		return out;
  	}