code: public static long seekBack(File f, int count, String marker) throws IOException {
          return seekBack(f, count, marker, null);
      }
docs: seekBack searches backwards for certain markers in a file, and returns position of the final marker found.
  count specifies how many markers to search for.  if the search reaches the beginning of the file without finding
  all of the markers, then 0 is returned.
  @param f the file to search
  @param count number of markers to find
  @param marker text string marker
  @return location of marker number <i>count</i> found from the end of the file, or 0
  @throws IOException