public Task ValidateAsync(ResourceOwnerPasswordValidationContext context)
        {
            var context1 = new ETContext();
            var user     = context1.Users.Where(u => u.EmailId == context.UserName && u.Password == context.Password).ToList();

            if (user.Count == 0)
            {
                //context.Result = new GrantValidationResult(TokenErrors.InvalidRequest, "User name or password is incorrect");
                context.Result = new GrantValidationResult(TokenRequestErrors.InvalidGrant, "invalid custom credential");
                return(Task.FromResult(0));
            }
            else
            {
                context.Result = new GrantValidationResult(context.UserName, "password");
                return(Task.FromResult(context));
            }
        }