setMethods.ts(13,17): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
  Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size
setMethods.ts(19,24): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
  Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size
setMethods.ts(25,22): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
  Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size
setMethods.ts(31,31): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
  Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size
setMethods.ts(37,22): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
  Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size
setMethods.ts(43,24): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
  Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size
setMethods.ts(49,26): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
  Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size


==== setMethods.ts (7 errors) ====
    let numberSet = new Set([0, 1, 2]);
    
    let stringSet = new Set(["a", "b"]);
    
    let numberMap = new Map([[4, {}], [5, {}]]);
    
    let numberSetLike = {
      size: 1,
      *keys() { yield 3 },
      has(x) { return x === 3 },
    };
    
    numberSet.union([]);
                    ~~
!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
!!! error TS2345:   Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size
    numberSet.union(new Set);
    numberSet.union(stringSet);
    numberSet.union(numberMap);
    numberSet.union(numberSetLike);
    
    numberSet.intersection([]);
                           ~~
!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
!!! error TS2345:   Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size
    numberSet.intersection(new Set);
    numberSet.intersection(stringSet);
    numberSet.intersection(numberMap);
    numberSet.intersection(numberSetLike);
    
    numberSet.difference([]);
                         ~~
!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
!!! error TS2345:   Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size
    numberSet.difference(new Set);
    numberSet.difference(stringSet);
    numberSet.difference(numberMap);
    numberSet.difference(numberSetLike);
    
    numberSet.symmetricDifference([]);
                                  ~~
!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
!!! error TS2345:   Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size
    numberSet.symmetricDifference(new Set);
    numberSet.symmetricDifference(stringSet);
    numberSet.symmetricDifference(numberMap);
    numberSet.symmetricDifference(numberSetLike);
    
    numberSet.isSubsetOf([]);
                         ~~
!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
!!! error TS2345:   Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size
    numberSet.isSubsetOf(new Set);
    numberSet.isSubsetOf(stringSet);
    numberSet.isSubsetOf(numberMap);
    numberSet.isSubsetOf(numberSetLike);
    
    numberSet.isSupersetOf([]);
                           ~~
!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
!!! error TS2345:   Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size
    numberSet.isSupersetOf(new Set);
    numberSet.isSupersetOf(stringSet);
    numberSet.isSupersetOf(numberMap);
    numberSet.isSupersetOf(numberSetLike);
    
    numberSet.isDisjointFrom([]);
                             ~~
!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'ReadonlySetLike<unknown>'.
!!! error TS2345:   Type 'undefined[]' is missing the following properties from type 'ReadonlySetLike<unknown>': has, size
    numberSet.isDisjointFrom(new Set);
    numberSet.isDisjointFrom(stringSet);
    numberSet.isDisjointFrom(numberMap);
    numberSet.isDisjointFrom(numberSetLike);
    