def inline_diff(line, start, ending)
        if start != 0 || ending != 0
          last = ending + line.length
          str = line[0...start] + '\0' + line[start...last] + '\1' + line[last...line.length]
        end
        str || line
      end
def inline_diff(line, start, ending)
        if start != 0 || ending != 0
          last = ending + line.length
          str = line[0...start] + '\0' + line[start...last] + '\1' + line[last...line.length]
        end
        str || line
      end
Inserts string formating characters around the section of a string
 that differs internally from another line so that the Line class
 can insert the desired formating