xSprite">FlxSprite</a></code>, <code>Enemy</code>, etc)
into the group at the specified position.
<code><a href="../../flixel/group/FlxGroup.html#FlxGroup">FlxGroup</a></code> will try to replace a <code>null</code> member at the specified position of the array first.
Failing that, <code><a href="../../flixel/group/FlxGroup.html#FlxGroup">FlxGroup</a></code> will insert it at the position of the member array.
WARNING: If the group has a <code>maxSize</code> that has already been met,
the object will NOT be 