presto-accumulo/src/main/java/io/prestosql/plugin/accumulo/serializers/AccumuloRowSerializer.java/AccumuloRowSerializer/getMapFromBlock
class AccumuloRowSerializer:    static Map<Object, Object> getMapFromBlock(Type type, Block block)
    {
        Map<Object, Object> map = new HashMap<>(block.getPositionCount() / 2);
        Type keyType = Types.getKeyType(type);
        Type valueType = Types.getValueType(type);
        for (int i = 0; i < block.getPositionCount(); i += 2) {
            map.put(readObject(keyType, block, i), readObject(valueType, block, i + 1));
        }
        return map;
    }