@Override
		protected void validateInputs(List<Varnode> inVars)
				throws PcodeExecutionException {
			if (inVars.size() != paramsIn.size()) {
				throw new PcodeExecutionException(
					"Incorrect input parameter count for userop " +
						method.getName() + ". Expected " + paramsIn.size() + " but got " +
						inVars.size());
			}
		}
An annotated userop with a fixed number of arguments

@param <T> the type of data processed by the userop
Ghidra/Framework/Emulation/src/main/java/ghidra/pcode/exec/AnnotatedPcodeUseropLibrary.java