lib/active_migration/key_mapper.rb
def mapped_key(map, key)
      load_keymap(map.to_s)
      @maps[map.to_s][handle_composite(key)]
    end
def mapped_key(map, key)
      load_keymap(map.to_s)
      @maps[map.to_s][handle_composite(key)]
    end
Returns the deserialized mapped key when provided with the former key.

  mapped_key(:products, 2)