presto-main/src/main/java/io/prestosql/metadata/InternalBlockEncodingSerde.java/InternalBlockEncodingSerde/readBlock
class InternalBlockEncodingSerde:    @Override
    public Block readBlock(SliceInput input)
    {
        // read the encoding name
        String encodingName = readLengthPrefixedString(input);

        // look up the encoding factory
        BlockEncoding blockEncoding = metadata.getBlockEncoding(encodingName);

        // load read the encoding factory from the output stream
        return blockEncoding.readBlock(this, input);
    }