docs: def diff_to_new_interesting_lines(unified_diff_lines: List[str]
                                    ) -> Dict[int, str]:
      """
      Extracts a set of 'interesting' lines out of a GNU unified diff format.
  
      Format:
        gnu.org/software/diffutils/manual/html_node/Detailed-Unified.html
  
        @@ from-line-numbers to-line-numbers @@
          line-from-either-file
          ...
        @@ start,count start,count @@
          line-from-either-file
          ...
        @@ single start,count @@
          line-from-either-file
          ...
      Examples:
        Deleted line (5 is the deleted LOC, 7 is the guessed would-have-been loc
        in the updated file given other changes pushing the line around):
          @@ 5 7,0 @@
           - content-of-line
  
        Added line:
          @@ 5,0 7 @@
           + content-of-line
  
        Modified chunk:
          @@ 10,15 11,5 @@
           - removed-line
           + added-line
           ...
  
      Args:
          unified_diff_lines: Lines of output from git diff.
      Returns:
          A dictionary of "touched lines", with key equal to the line number and
          value equal to the reason the line was touched. Includes added lines
          and lines near changes (including removals).
      """
      interesting_lines = dict()
      for diff_line in unified_diff_lines:
          # Parse the 'new file' range parts of the unified diff.
          if not diff_line.startswith('@@ '):
              continue
          change = diff_line[3:diff_line.index(' @@', 3)]
          new = change.split(' ')[1]
          start = int(new.split(',')[0])
          count = 1 if ',' not in new else int(new.split(',')[1])
  
          # The lines before and after a deletion should still be covered.
          if count == 0:
              for i in range(start, start + 2):
                  interesting_lines[i] = 'is near a removal'
          else:
              for i in range(start, start + count):
                  interesting_lines[i] = 'is new or changed'
      return interesting_lines