return modelSource.getLocation();
                }

                @Override
                public Source resolve(String relative) {
                    if (modelSource instanceof ModelSource2 ms) {
                        return toSource(ms.getRelatedSource(relative));
                    } else {
                        return null;
                    }
                }
            };
        }

        }

        return false;
    }

    /**
     * Compares two model versions.
     *
     * @param first the first version.
     * @param second the second version.
     * @return negative if the first version is newer than the second version, zero if they are the same or positive if
     * the second version is the newer.
     */
    private static int compareModelVersions(String first, String second) {