private function constructor(string $class_name, array $params = null)
    {
        $this->state->category = CompilerState::CATEGORY_CONSTRUCTOR;
        $this->state->name = '';
        $params_str = '';
        if (is_array($params)){
            $params_str = $this->decorateParamsForMethodCall($params);
        }
        return $class_name . '(' . $params_str . ')';
    }