How to use

checkStack

method

in

org.lsmp.djep.groupJep.function.GUMinus

/**
 * Calculates the result of applying the "+" operator to the arguments from
 * the stack and pushes it back on the stack.
 */
public void run(Stack stack) throws ParseException {
  checkStack(stack);// check the stack
  
  Object sum = stack.pop();
  stack.push(uminus(sum));
  return;
}

/**
 * Calculates the result of applying the "+" operator to the arguments from
 * the stack and pushes it back on the stack.
 */
public void run(Stack stack) throws ParseException {
  checkStack(stack);// check the stack
  
  Object sum = stack.pop();
  stack.push(uminus(sum));
  return;
}