code: @CheckForNull
    public Map<Path, Set<Integer>> branchChangedLines(String targetBranchName, Path rootBaseDir, Set<Path> files) {
      return null;
    }
docs: Return a map between paths given as argument and the corresponding line numbers which are new compared to the provided target branch.
  If null is returned or if a path is not included in the map, an imprecise fallback mechanism will be used to detect which lines
  are new (based on SCM dates).
  
  @param files Absolute path of files of interest
  @return null if the SCM provider was not able to compute the new lines
  @since 7.4