mori: Modify set constructors to allow creation of empty sets
mori: Modify set constructors to allow creation of empty sets

altano/flow-typed,mkscrg/flow-typed,hansonw/flow-typed,hansonw/flow-typed,mkscrg/flow-typed,gaborsar/flow-typed,davidohayon669/flow-typed,mwalkerwells/flow-typed,orlandoc01/flow-typed,splodingsocks/FlowTyped,gaborsar/flow-typed,doberkofler/flow-typed,nmn/FlowTyped,nmn/FlowTyped,davidohayon669/flow-typed,flowtype/flow-typed,orlandoc01/flow-typed,doberkofler/flow-typed,LegNeato/flow-typed,mwalkerwells/flow-typed,echenley/flow-typed,altano/flow-typed,splodingsocks/FlowTyped,LegNeato/flow-typed,echenley/flow-typed,flowtype/flow-typed