This act shall take effect as provided by the Constitution of the State of Illinois, provided that the State of Missouri shall then have enacted into law legislation having an identical effect with this act. In the event that legislation of identical effect with this act shall not have been enacted into law in the State of Missouri on the date when this act would otherwise become effective in this state, then this act shall not become effective until such time as such legislation shall have been enacted into law by the State of Missouri.
45 ILCS 110/4