parameters: (filesystem, paths, skipped_directories, file_filter, directory_sort_key)
return_statement: return all_files
docstring: Finds the set of tests under the list of paths.
  
      Args:
        paths: a list of absolute path expressions to search.
            Glob patterns are ok.
docstring_summary: Finds the set of tests under the list of paths.
docstring_tokens: Finds the set of tests under the list of paths .
function: def _normalized_find(filesystem, paths, skipped_directories, file_filter, directory_sort_key):
      """Finds the set of tests under the list of paths.
  
      Args:
        paths: a list of absolute path expressions to search.
            Glob patterns are ok.
      """
  
      paths_to_walk = itertools.chain(*(filesystem.glob(path) for path in paths))
  
      def sort_by_directory_key(files_list):
          if directory_sort_key:
              files_list.sort(key=directory_sort_key)
          return files_list
  
      all_files = itertools.chain(*(sort_by_directory_key(filesystem.files_under(path, skipped_directories, file_filter)) for path in paths_to_walk))
      return all_files
function_tokens: def _normalized_find ( filesystem , paths , skipped_directories , file_filter , directory_sort_key ) : paths_to_walk = itertools . chain ( * ( filesystem . glob ( path ) for path in paths ) ) def sort_by_directory_key ( files_list ) : if directory_sort_key : files_list . sort ( key = directory_sort_key ) return files_list all_files = itertools . chain ( * ( sort_by_directory_key ( filesystem . files_under ( path , skipped_directories , file_filter ) ) for path in paths_to_walk ) ) return all_files