docs: def merge_conflicts(self):
          """The filenames of any files with merge conflicts (a list of strings)."""
          filenames = set()
          listing = self.context.capture('hg', 'resolve', '--list')
          for line in listing.splitlines():
              tokens = line.split(None, 1)
              if len(tokens) == 2:
                  status, name = tokens
                  if status and name and status.upper() != 'R':
                      filenames.add(name)
          return sorted(filenames)