@Override
                public ConfigDefinition parse() {
                    DefParser parser = new DefParser(key.getName(), retrieveConfigDefReader(def));
                    return ConfigDefinitionBuilder.createConfigDefinition(parser.getTree());
                }
Creates a reader for a config definition

@param defPath the path to the application package
@return the reader of this config definition
config-application-package/src/main/java/com/yahoo/config/model/application/provider/FilesApplicationPackage.java