docs: def _get_local_files(local_dir, pattern=''):
      """
      Returns a dictionary with directories as keys, and filenames as values
      for filenames matching the glob ``pattern`` under the ``local_dir``
      ``pattern can contain the Boolean OR | to evaluated multiple patterns into
      a combined set. 
      """
      local_files = {}
      
      if pattern:
          cwd = os.getcwd()
          os.chdir(local_dir)
          patterns = pattern.split('|')
          local_list = set([])
          for p in patterns: local_list = local_list | set(glob(p))
          for path in local_list:
              dir, file = os.path.split(path)
              if os.path.isfile(path):
                  local_files[dir] = local_files.get(dir,[])+[file]
              elif os.path.isdir(path):
                  local_files[file] = local_files.get(dir,[])
          os.chdir(cwd)
      return local_files