Sec. 4.011. MEMBERSHIP OF FIRE CHIEF AND CHIEF OF POLICE. Not later than the 30th day after the date a fire chief or a chief of police of a municipality assumes office, the fire chief or chief of police may make an irrevocable election to not become a member of the fund or to terminate membership in the fund by delivering written notice of such election to the secretary of the board. A fire chief or chief of police who does not make an election under this subsection is considered to have chosen to become or to remain a member of the fund.