class XorShift128Plus { /* constants */ protected const MASK_S5 = 0x07ffffffffffffff; protected const MASK_S18 = 0x00003fffffffffff; protected const MASK_S27 = 0x0000001fffffffff; protected const MASK_S30 = 0x00000003ffffffff; protected const MASK_S31 = 0x00000001ffffffff; protected const MASK_LO = 0x00000000ffffffff; protected const ADD_HI = 0x9e3779b9; protected const ADD_LO = 0x7f4a7c15; protec