code: private void checkUnique(Variable var) {
  		if (inputs.containsKey(var.getName())) {
  			throw new FuzzerException(var.getName() + ": already defined");
  		}
  		if (outputs.containsKey(var.getName())) {
  			throw new FuzzerException(var.getName() + ": already defined");
  		}
  	}
docs: Check if a variable is unique.
  <p>
  @param var the variable