code: public void addSrcSetWidthVariants(int minWidth, int maxWidth) {
  
          int imageWidth = getWidth();
          if (imageWidth > minWidth) {
              // only add variants in case the image is larger then the given minimum
              int srcSetMaxWidth = getSrcSetMaxWidth();
              for (double factor : m_sizeVariants) {
                  long width = Math.round(imageWidth * factor);
                  if (width > srcSetMaxWidth) {
                      if (width <= maxWidth) {
                          setSrcSets(createWidthVariation(String.valueOf(width)));
                      }
                  } else {
                      break;
                  }
              }
          }
      }
docs: Adds a number of size variations to the source set.<p>
  
  In case the screen size is not really known, it may be a good idea to add
  some variations for large images to make sure there are some common options in case the basic
  image is very large.<p>
  
  @param minWidth the minimum image width to add size variations for
  @param maxWidth the maximum width size variation to create