protected String stringifyUserop(Language language, int id) {
		String pseudoOp = stringifyUseropUnchecked(language, id);
		if (pseudoOp == null) {
			Msg.error(this, "Pseudo-op index not found: " + id);
			pseudoOp = "unknown";
		}
		return pseudoOp;
	}
Convert a given userop to a string as it should be conventionally displayed.

@param language the langauge containing the userop
@param id the userop id
@return the display string, i.e., its name or "unknown"
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/util/pcode/AbstractAppender.java