@Override
	public void decode(Decoder decoder, SleighLanguage lang) throws DecoderException {
		int el = decoder.openElement(ELEM_CONTEXT_OP);
		num = (int) decoder.readSignedInteger(ATTRIB_I);
		shift = (int) decoder.readSignedInteger(ATTRIB_SHIFT);
		mask = (int) decoder.readUnsignedInteger(ATTRIB_MASK);
		patexp = PatternExpression.decodeExpression(decoder, lang);
		decoder.closeElement(el);
	}
An operation on the context (bit-packed form) of an instruction
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/processors/sleigh/ContextOp.java