New Set methods

Specification
Proposal repo

Built-ins signatures

class Set {
  difference(other: SetLike<mixed>): Set;
  intersection(other: SetLike<mixed>): Set;
  isDisjointFrom(other: SetLike<mixed>): boolean;
  isSubsetOf(other: SetLike<mixed>): boolean;
  isSupersetOf(other: SetLike<mixed>): boolean;
  symmetricDifference(other: SetLike<mixed>): Set;
  union(other: SetLike<mixed>): Set;
}

Entry points

core-js/proposals/set-methods-v2