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

        public virtual bool IsInRole(string role)
        {
            for (int i = 0; i < _identities.Count; i++)
            {
                if (_identities[i] != null)
                {
                    if (_identities[i].HasClaim(_identities[i].RoleClaimType, role))
                    {
                        return true;
                    }
                }
            }

            return false;
        }

        /// <summary>
        /// Filter list of users based on availability.
        /// </summary>
        /// <param name="users">Sequence of users.</param>
        /// <param name="principal">Principal which is used for accessing data.</param>
        /// <returns>Filter sequence with applied security rules.</returns>
        protected virtual IQueryable <TUser> FilterUsers(IQueryable <TUser> users, System.Security.Claims.ClaimsPrincipal principal)
        {
            if (principal == null)
            {
                throw new ArgumentNullException("principal");
            }

            if (users == null)
            {
                throw new ArgumentNullException("users");
            }

            if (principal.IsInRole(RoleNames.Administrator))
            {
                return(users);
            }

            if (principal.IsInRole(RoleNames.ClientAdministrator))
            {
                var clientId = principal.GetClient();
                users = users.Cast <DubUserWithClient>()
                        .Where(_ => _.ClientId == clientId)
                        .Cast <TUser>();
            }

            return(Enumerable.Empty <TUser>().AsQueryable());
        }