code: def _compute_sync_map_file_path(
              self,
              root,
              hierarchy_type,
              custom_id,
              file_name
      ):
          
          prefix = root
          if hierarchy_type == HierarchyType.PAGED:
              prefix = gf.norm_join(prefix, custom_id)
          file_name_joined = gf.norm_join(prefix, file_name)
          return self._replace_placeholder(file_name_joined, custom_id)
docs: Compute the sync map file path inside the output container.
  
          :param string root: the root of the sync map files inside the container
          :param job_os_hierarchy_type: type of job output hierarchy
          :type  job_os_hierarchy_type: :class:`~aeneas.hierarchytype.HierarchyType`
          :param string custom_id: the task custom id (flat) or
                                   page directory name (paged)
          :param string file_name: the output file name for the sync map
          :rtype: string