@Override
	public void decode(Decoder decoder, SleighLanguage lang) throws DecoderException {
		int el = decoder.openElement(ELEM_START_EXP);
		decoder.closeElement(el);
		// Nothing to do
	}
The offset value of the current instructions address
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/processors/sleigh/expression/StartInstructionValue.java