code: def ls(self, mdir, limit=None, marker=None):
          
          assert limit is None and marker is None, "not yet implemented"
          dirents = {}
  
          if limit or marker:
              entries = self.list_directory(mdir, limit=limit, marker=marker)
              for entry in entries:
                  dirents[entry["name"]] = entry
  
          else:
              marker = None
              while True:
                  res, entries = self.list_directory2(mdir, marker=marker)
                  if marker:
                      entries.pop(0)  # first one is a repeat (the marker)
                  if not entries:
                      # Only the marker was there, we've got them all.
                      break
                  for entry in entries:
                      if "id" in entry:  # GET /:account/jobs
                          dirents[entry["id"]] = entry
                      else:
                          dirents[entry["name"]] = entry
                  if marker is None:
                      # See if got all results in one go (quick out).
                      result_set_size = int(res.get("result-set-size", 0))
                      if len(entries) == result_set_size:
                          break
                  if "id" in entries[-1]:
                      marker = entries[-1]["id"]  # jobs
                  else:
                      marker = entries[-1]["name"]
  
          return dirents
docs: List a directory.
  
          Dev Notes:
          - If `limit` and `marker` are *not* specified. This handles paging
            through a directory with more entries than Manta will return in
            one request (1000).
          - This returns a dict mapping name to dirent as a convenience.
            Note that that makes this inappropriate for streaming a huge
            listing. A streaming-appropriate `ls` will be a separate method
            if/when that is added.
  
          @param mdir {str} A manta directory, e.g. '/trent/stor/a-dir'.
          @returns {dict} A mapping of names to their directory entry (dirent).