public byte [] decompress(byte[] input, int uncompressedLen) {
        return compressor.decompressUnconditionally(input, 0, uncompressedLen);
    }
Wrapper for LZ4 compression that selects compression level based on properties.

@author Ulf Lilleengen
config/src/main/java/com/yahoo/vespa/config/LZ4PayloadCompressor.java