@Override
	public void decode(Decoder decoder, SleighLanguage lang) throws DecoderException {
		int el = decoder.openElement();

		unary = PatternExpression.decodeExpression(decoder, lang);
		decoder.closeElement(el);
	}
Base class for unary operators on PatternExpressions
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/processors/sleigh/expression/UnaryExpression.java