code: def calculate_file_access_time(workflow_workspace):
      
      access_times = {}
      for subdir, dirs, files in os.walk(workflow_workspace):
          for file in files:
              file_path = os.path.join(subdir, file)
              access_times[file_path] = os.stat(file_path).st_atime
      return access_times
docs: Calculate access times of files in workspace.