public function isDateAvailable()
    {
        // @todo For now, any out of scope variable inside of "beforeShowDay" method will be undefined.
        // @link https://github.com/refactoror/SelBlocks/issues/5#issuecomment-68511965
        $beforeShowDay = $this->datePicker(['option', 'beforeShowDay']);

        if (!empty($beforeShowDay) && !empty($this->execute("$beforeShowDay($this->date)")[0])) {
            throw new \Exception(sprintf('The "%s" is not available for choosing.', $this->date));
        }

        return $this;
    }
public function isDateAvailable()
    {
        // @todo For now, any out of scope variable inside of "beforeShowDay" method will be undefined.
        // @link https://github.com/refactoror/SelBlocks/issues/5#issuecomment-68511965
        $beforeShowDay = $this->datePicker(['option', 'beforeShowDay']);

        if (!empty($beforeShowDay) && !empty($this->execute("$beforeShowDay($this->date)")[0])) {
            throw new \Exception(sprintf('The "%s" is not available for choosing.', $this->date));
        }

        return $this;
    }
@throws \Exception

@return self