code: public int getArgumentSlot(int i, int numArguments) {
          if (i >= numArguments) {
              throw new IllegalArgumentException();
          }
  
          return (slotList.size() - numArguments) + i;
      }
docs: Get the stack slot that will contain given method argument. Assumes that
  this frame is at the location (just before) a method invocation
  instruction.
  
  @param i
  the argument index: 0 for first arg, etc.
  @param numArguments
  total number of arguments to the called method
  @return slot containing the argument value