test

public static function fieldsCallback(){
		$this_ = Self::newWithoutConstructor();

		if(method_exists($this_, 'cmb2Fields')){
			$fields = $this_->cmb2Fields();

			if(function_exists('new_cmb2_box') && is_array($fields)){
				if(!isset($fields['meta_box'])){
					$fields['meta_box'] = [
						'id'            => get_called_class(),
						'title'         => get_called_class(),
						'object_types'  => array($this_->postType),
					];
				}

				$cmb = new_cmb2_box($fields['meta_box']);
				unset($fields['meta_box']);

				foreach($fields as $field){
					$cmb->add_field($field);
				}	
			}
		}
	}
	
	
	
	public function cmb2Fields(){
		return [
			[
				'name' => 'Test Text',
				'id'   => 'text',
				'type' => 'text',
			],[
				'name' => 'Website URL', 'cmb2',
				'id'   => 'url',
				'type' => 'text_url',
			]
		];
	}
	
	
		add_action('cmb2_admin_init', [get_called_class(), 'fieldsCallback']);