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