protected final String readExpressionFromFile(File file) throws IOException {
        return (file.getName().endsWith(".lz4"))
            ? Utf8.toString(IOUtils.readBytes(new LZ4FrameInputStream(new FileInputStream(file)), 65536))
            : Utf8.toString(IOUtils.readFileBytes(file));
    }
Returns a map of the models contained in this config, indexed on name.
The map is modifiable and owned by the caller.
model-evaluation/src/main/java/ai/vespa/models/evaluation/RankProfilesConfigImporter.java