private static bool ValidateToken(string token, out string username)
        {
            username = null;

            var simplePrinciple = JwtAuthManager.GetPrincipal(token);
            var identity        = simplePrinciple?.Identity as ClaimsIdentity;

            if (identity == null)
            {
                return(false);
            }

            if (!identity.IsAuthenticated)
            {
                return(false);
            }

            var usernameClaim = identity.FindFirst(ClaimTypes.Name);

            username = usernameClaim?.Value;

            if (string.IsNullOrEmpty(username))
            {
                return(false);
            }

            /*VALIDA SE O UTILIZADOR EXISTE**/
            if (!AuthUser.UserExists(username))
            {
                return(false);
            }

            return(true);
        }