code: @Nonnegative
    public static int getSize (@Nullable final Iterator <?> aIterator)
    {
      int ret = 0;
      if (aIterator != null)
        while (aIterator.hasNext ())
        {
          aIterator.next ();
          ++ret;
        }
      return ret;
    }
docs: Retrieve the size of the passed {@link Iterator}.
  
  @param aIterator
  Iterator to check. May be <code>null</code>.
  @return The number objects or 0 if the passed parameter is
  <code>null</code>.