public function validate()
    {
        $this->required('Bucket');

        $count_add = count($this->add_all);
        $count_remove = count($this->remove_all);

        if ($count_add + $count_remove < 1) {
            throw new Exception('At least one element to add or remove needs to be defined.');
        }

        // if we are performing a remove, Location and context are required
        if ($count_remove) {
            $this->required('Location');
            $this->required('Context');
        }
    }
public function validate()
    {
        $this->required('Bucket');

        $count_add = count($this->add_all);
        $count_remove = count($this->remove_all);

        if ($count_add + $count_remove < 1) {
            throw new Exception('At least one element to add or remove needs to be defined.');
        }

        // if we are performing a remove, Location and context are required
        if ($count_remove) {
            $this->required('Location');
            $this->required('Context');
        }
    }
{@inheritdoc}