Returns true if there is a one-to-one relationship between every key-value pair.
public static bool AreEqual<TKey, TValue>(IReadOnlyDictionary<TKey, TValue>? left,
IReadOnlyDictionary<TKey, TValue>? right, IEqualityComparer<TValue>? comparer = null)
Uses the default equality comparer for TValue if none is specified.