System.Security.Claims.ClaimsPrincipal.SelectPrimaryIdentity C# (CSharp) Method

        static ClaimsIdentity SelectPrimaryIdentity(IEnumerable<ClaimsIdentity> identities)
        {
            if (identities == null)
            {
                throw new ArgumentNullException(nameof(identities));
            }

            foreach (ClaimsIdentity identity in identities)
            {
                if (identity != null)
                {
                    return identity;
                }
            }

            return null;
        }