docs: function clientLogin(clientId, clientSecret, done) {
          debug('clientLogin: %s', clientId);
  
          clientId = parseInt(clientId);
          if (!clientId && clientId !== 0) {
              return done(null, false);
          }
  
          models.Clients.findByClientId(clientId, function (err, client) {
              if (err) {
                  return done(err);
              }
              if (!client) {
                  return done(null, false);
              }
              var secret = client.clientSecret || client.restApiKey;
              if (secret !== clientSecret) {
                  return done(null, false);
              }
              return done(null, client);
          });
      }