Update LKG

lib/lib.esnext.collection.d.ts

@@ -27,3 +27,80 @@ interface MapConstructor {
         keySelector: (item: T, index: number) => K,
     ): Map<K, T[]>;
 }
+
+interface ReadonlySetLike<T> {
+    /**
+     * Despite its name, returns an iterator of the values in the set-like.
+     */
+    keys(): Iterator<T>;
+    /**
+     * @returns a boolean indicating whether an element with the specified value exists in the set-like or not.
+     */
+    has(value: T): boolean;
+    /**
+     * @returns the number of (unique) elements in the set-like.
+     */
+    readonly size: number;
+}
+
+interface Set<T> {
+    /**
+     * @returns a new Set containing all the elements in this Set and also all the elements in the argument.
+     */
+    union<U>(other: ReadonlySetLike<U>): Set<T | U>;
+    /**
+     * @returns a new Set containing all the elements which are both in this Set and in the argument.
+     */
+    intersection<U>(other: ReadonlySetLike<U>): Set<T & U>;
+    /**
+     * @returns a new Set containing all the elements in this Set which are not also in the argument.
+     */
+    difference<U>(other: ReadonlySetLike<U>): Set<T>;
+    /**
+     * @returns a new Set containing all the elements which are in either this Set or in the argument, but not in both.
+     */
+    symmetricDifference<U>(other: ReadonlySetLike<U>): Set<T | U>;
+    /**
+     * @returns a boolean indicating whether all the elements in this Set are also in the argument.
+     */
+    isSubsetOf(other: ReadonlySetLike<unknown>): boolean;
+    /**
+     * @returns a boolean indicating whether all the elements in the argument are also in this Set.
+     */
+    isSupersetOf(other: ReadonlySetLike<unknown>): boolean;
+    /**
+     * @returns a boolean indicating whether this Set has no elements in common with the argument.
+     */
+    isDisjointFrom(other: ReadonlySetLike<unknown>): boolean;
+}
+
+interface ReadonlySet<T> {
+    /**
+     * @returns a new Set containing all the elements in this Set and also all the elements in the argument.
+     */
+    union<U>(other: ReadonlySetLike<U>): Set<T | U>;
+    /**
+     * @returns a new Set containing all the elements which are both in this Set and in the argument.
+     */
+    intersection<U>(other: ReadonlySetLike<U>): Set<T & U>;
+    /**
+     * @returns a new Set containing all the elements in this Set which are not also in the argument.
+     */
+    difference<U>(other: ReadonlySetLike<U>): Set<T>;
+    /**
+     * @returns a new Set containing all the elements which are in either this Set or in the argument, but not in both.
+     */
+    symmetricDifference<U>(other: ReadonlySetLike<U>): Set<T | U>;
+    /**
+     * @returns a boolean indicating whether all the elements in this Set are also in the argument.
+     */
+    isSubsetOf(other: ReadonlySetLike<unknown>): boolean;
+    /**
+     * @returns a boolean indicating whether all the elements in the argument are also in this Set.
+     */
+    isSupersetOf(other: ReadonlySetLike<unknown>): boolean;
+    /**
+     * @returns a boolean indicating whether this Set has no elements in common with the argument.
+     */
+    isDisjointFrom(other: ReadonlySetLike<unknown>): boolean;
+}