System.Security.Claims.ClaimsPrincipal.ClaimsPrincipal C# (CSharp) Метод

        public ClaimsPrincipal(IPrincipal principal)
        {
            if (null == principal)
            {
                throw new ArgumentNullException(nameof(principal));
            }

            Contract.EndContractBlock();

            //
            // If IPrincipal is a ClaimsPrincipal add all of the identities
            // If IPrincipal is not a ClaimsPrincipal, create a new identity from IPrincipal.Identity
            //
            ClaimsPrincipal cp = principal as ClaimsPrincipal;
            if (null == cp)
            {
                _identities.Add(new ClaimsIdentity(principal.Identity));
            }
            else
            {
                if (null != cp.Identities)
                {
                    _identities.AddRange(cp.Identities);
                }
            }
        }