Opencart 2.x - save settings for module or add module to layout

//loading the settings
$this->load->model('setting/setting');
$setting = $this->model_setting_setting->getSetting('mymodule');
//saving the settings
$this->load->model('setting/setting');
$setting = $this->model_setting_setting->editSetting('mymodule');

NOTE: in the form the input name="" must start with the name of the module. Example: mymodule_limit, mymodule_status, mymodule_othersetting


//getting data from the module - usually is loaded by the configured layout
        $this->load->model('extension/module');
$setting = $this->model_extension_module->getModuleByCode('mymodule');

//saving data for the module with new id from the POST (saves a new one that can be loaded from the layout)
        $this->load->model('extension/module');
               if (!isset($this->request->get['module_id'])) { // $this->model_extension_module->addModule('mymodule', $this->request->post);
                } else {
                $this->model_extension_module->editModule($this->request->get['module_id'], $this->request->post);
                }