# File lib/preferences.rb, line 209 def register_pref_key(obj, key) obj_id = obj.object_id if metadata[obj_id] unless Metadata.normalize(key) == metadata[obj_id].key raise ConfigError, "Cannot register #{key}. Already registered a preferences key " + "for this object, #{metadata[obj_id].key}." end else metadata[obj_id] = Metadata.new(preferences, key) end key end