private function sortRegisteredServices()
    {
        krsort($this->formConfigurationModifiers);
        if ( ! empty($this->formConfigurationModifiers)) {
            $this->sortedFormConfigurationModifiers = call_user_func_array('array_merge', $this->formConfigurationModifiers);
        }
        krsort($this->formFieldResolvers);
        if ( ! empty($this->formFieldResolvers)) {
            $this->sortedFormFieldResolvers = call_user_func_array('array_merge', $this->formFieldResolvers);
        }
        krsort($this->formViewProviders);
        if ( ! empty($this->formViewProviders)) {
            $this->sortedFormViewProviders = call_user_func_array('array_merge', $this->formViewProviders);
        }
    }