@Override
    public void writeInt32(int fieldNumber, int value, boolean repeated) throws IOException
    {
        if (value < 0)
        {
            tail = writeTagAndRawVarInt64(
                    makeTag(fieldNumber, WIRETYPE_VARINT),
                    value,
                    this,
                    tail);
        }
        else
        {
            tail = writeTagAndRawVarInt32(
                    makeTag(fieldNumber, WIRETYPE_VARINT),
                    value,
                    this,
                    tail);
        }
    }
Resets this output for re-use.
protostuff-core/src/main/java/io/protostuff/ProtobufOutput.java