Transformer/ConditionTrait.php
protected function checkEmpty($input, $key)
    {
        $currentValue = $this->getValue($input, $key);

        return empty($currentValue);
    }
protected function checkEmpty($input, $key)
    {
        $currentValue = $this->getValue($input, $key);

        return empty($currentValue);
    }
Check if the input property is empty or not

@param array|object $input
@param string       $key

@return bool