docs: function forFeature( featurePath ) {
        assert( featurePath ).hasType( String ).isNotNull();
        if( handlers[ featurePath ] ) {
           return handlers[ featurePath ];
        }
  
        const locale = path( features, `${featurePath}.locale` );
        assert( locale ).hasType( String ).isNotNull(
           `axI18n: missing feature-configuration '${featurePath}.locale' (widget: ${widget.id})`
        );
  
        const api = forLocale( locale, featurePath );
        handlers[ featurePath ] = api;
        return api;
     }