/// <summary>
        /// Reverts impersonation of a security context
        /// </summary>
        public void RevertContext()
        {
            // check object state
            if (_disposed)
            {
                throw new ObjectDisposedException(GetType().FullName);
            }

            // revert impersonation
            int error = SSPINative.RevertSecurityContext(ref _contextHandle);

            if (error < 0)
            {
                throw new SSPIException(error, "Could not revert security context impersonation");
            }
        }