class MigrationPaths {

    MigrationPath getMigrationPath(URI inputFormat, URI outputFormat)
	    throws NoSuchPathException {

	final PathKey pathKey = new PathKey(inputFormat, outputFormat);
	final MigrationPath migrationPath = this.migrationPaths.get(pathKey);
	if (migrationPath == null) {
	    throw new NoSuchPathException(
		    "No migration path found for input format URI=\""
			    + inputFormat + "\" and output format URI=\""
			    + outputFormat + "\"");
	}
	return migrationPath;
    }

      MigrationPaths();

}