code: private int computeAverageWidth(){
          int count = 0;
          int total = 0;
          for(int i = 0; i < super.widths.length; i++){
              if(super.widths[i] != 0){
                  total += super.widths[i];
                  count++;
              }
          }
          return count != 0 ? total/count : 0;
      }
docs: For all widths of all glyphs, compute the average width in normalized 1000 point units.
  This is used to give some meaningful width in cases where we need an average font width
  (such as if the width of a space isn't specified by a given font)
  @return the average width of all non-zero width glyphs in the font