I had defined an array as input name for Phalcon\Forms\Element\Select...when i try to add PresenceOf validator to it....then even after selecting multiple values the validator is throwing error msgs..." Choose atleast one Wallet Types".
        $corporate_wallets = new Select('wallets_subscribed[]', $wallets, array(
            'multiple' => 'multiple',
            'useEmpty' => TRUE,
            'emptyText' => 'Select Wallets',
            'emptyValue' => '',
        ));
        $corporate_wallets->addValidators(array(
            new PresenceOf(array(
                'message' => 'Choose atleast one  Wallet Types'
                    ))
        ));
        $corporate_wallets->setAttribute('id', 'wallettypes');
        $corporate_wallets->setLabel('Select Wallet Types');
        $this->add($corporate_wallets);