protected function isNullableKey($key)
    {
        if ( ! array_key_exists($key, $this->info->attributes)) {
            throw new RuntimeException(
                "Foreign key '{$key}' defined for relation does not exist on model " . get_class($this->model())
            );
        }

        return (bool) $this->info->attributes[ $key ]->nullable;
    }
protected function isNullableKey($key)
    {
        if ( ! array_key_exists($key, $this->info->attributes)) {
            throw new RuntimeException(
                "Foreign key '{$key}' defined for relation does not exist on model " . get_class($this->model())
            );
        }

        return (bool) $this->info->attributes[ $key ]->nullable;
    }
protected function isNullableKey ( $ key ) { if ( ! array_key_exists ( $ key , $ this -> info -> attributes ) ) { throw new RuntimeException ( "Foreign key '{$key}' defined for relation does not exist on model " . get_class ( $ this -> model ( ) ) ) ; } return ( bool ) $ this -> info -> attributes [ $ key ] -> nullable ; }
Returns whether attribute with key is known to be nullable.

@param string $key
@return bool
Returns whether attribute with key is known to be nullable .