code: public DepictionGenerator withSize(double w, double h) {
          if (w < 0 && h >= 0 || h < 0 && w >= 0)
              throw new IllegalArgumentException("Width and height must either both be automatic or both specified");
          DepictionGenerator copy = new DepictionGenerator(this);
          copy.dimensions = w == AUTOMATIC ? Dimensions.AUTOMATIC : new Dimensions(w, h);
          return copy;
      }
docs: Specify a desired size of depiction. The units depend on the output format with
  raster images using pixels and vector graphics using millimeters. By default depictions
  are only ever made smaller if you would also like to make depictions fill all available
  space use the {@link #withFillToFit()} option.
  
  Currently the size must either both be precisely specified (e.g. 256x256) or
  automatic (e.g. {@link #AUTOMATIC}x{@link #AUTOMATIC}) you cannot for example
  specify a fixed height and automatic width.
  
  @param w max width
  @param h max height
  @return new generator for method chaining
  @see #withFillToFit()