code: @Override
      public boolean add(final E element) {
          if (null == element) {
              throw new NullPointerException("Attempted to add null object to queue");
          }
  
          if (isAtFullCapacity()) {
              remove();
          }
  
          elements[end++] = element;
  
          if (end >= maxElements) {
              end = 0;
          }
  
          if (end == start) {
              full = true;
          }
  
          return true;
      }
docs: Adds the given element to this queue. If the queue is full, the least recently added
  element is discarded so that a new element can be inserted.
  
  @param element  the element to add
  @return true, always
  @throws NullPointerException  if the given element is null