old_contents: # Copyright (c) 2017 The Regents of the University of Michigan.
  # All Rights Reserved. Licensed according to the terms of the Revised
  # BSD License. See LICENSE.txt for details.
  
  class FakeMappingThatRecordsAccessions:
  
      def __init__ (self):
          self.__set = set()
  
      def __getitem__ (self, key):
          self.__set.add(key)
          return 0
  
      def get_set (self):
          return self.__set
  
      def check_on_format_str (self, format_str):
          format_str.format_map(self)
  
new_contents: # Copyright (c) 2017 The Regents of the University of Michigan.
  # All Rights Reserved. Licensed according to the terms of the Revised
  # BSD License. See LICENSE.txt for details.
  
  class FakeMappingThatRecordsAccessions:
  
      def __init__ (self):
          self.__set = set()
  
      def __getitem__ (self, key):
          self.__set.add(key)
          return 0
  
      def get_set (self):
          return self.__set
  
      def check_on_format_str (self, format_str):
          format_str.format_map(self)
  
  def get_expected_args_from_format_str (format_str):
      mapping = FakeMappingThatRecordsAccessions()
      format_str.format_map(mapping)
  
      return mapping.get_set()
  
subject: Write function for getting expected args