src/Model.php
protected function hasUnboundField($key)
    {
        $parts = $this->explodeKey($key);

        foreach ($parts as $part) {
            if ($this->isUnboundField($part)) {
                return true;
            }
        }

        return false;
    }
protected function hasUnboundField($key)
    {
        $parts = $this->explodeKey($key);

        foreach ($parts as $part) {
            if ($this->isUnboundField($part)) {
                return true;
            }
        }

        return false;
    }
protected function hasUnboundField ( $ key ) { $ parts = $ this -> explodeKey ( $ key ) ; foreach ( $ parts as $ part ) { if ( $ this -> isUnboundField ( $ part ) ) { return true ; } } return false ; }
Check a key whether has unbound field

@param $key
@return bool
Check a key whether has unbound field