namespace System.Text.RegularExpressions
{
    [DefaultMember("Item")]
    public class GroupCollection : ICollection<Group!>, IEnumerable, IEnumerable<KeyValuePair<string!, Group!>>, IEnumerable<Group!>, IList<Group!>, IReadOnlyCollection<KeyValuePair<string!, Group!>>, IReadOnlyCollection<Group!>, IReadOnlyDictionary<string!, Group!>, IReadOnlyList<Group!>, ICollection, IList
    {
        public bool ContainsKey(string! key);
    }
}