presto-orc/src/main/java/io/prestosql/orc/stream/LongDecode.java/LongDecode/readVInt
class LongDecode:    public static long readVInt(boolean signed, OrcInputStream inputStream)
            throws IOException
    {
        if (signed) {
            return readSignedVInt(inputStream);
        }
        else {
            return readUnsignedVInt(inputStream);
        }
    }