In Sgaglione v. Levitt, 37 N.Y.2d 507 [1975] the Court of Appeals recognized that in regard to the Retirement Systems, the Legislature reserved the flexibility to change the manner of paying contributions, to fund deficiencies in actuarial reserve, to authorize the investment of the funds, and to manage the funds. (See 37 N.Y.2d at 512.) The Court also stated that close examination is required of any radical change in the means chosen to maintain the integrity and security of the sources from which concededly protected benefits are to be paid. (Id.) Thus, the court must first determine whether the legislative action that resulted in chapter 411 falls within one of the limited areas of flexibility reserved by the Legislature and whether such action constitutes a radical change in the means chosen to maintain the integrity and security of benefit sources.