public function save_custom_taxonomy(){
    global $mf_domain;

    //checking the nonce
    check_admin_referer('form_custom_taxonomy_mf_custom_taxonomy');

    if(isset($_POST['mf_custom_taxonomy'])){
      //check custom_taxonomy_id
      $mf = $_POST['mf_custom_taxonomy'];
      if($mf['core']['id']){
        $this->update_custom_taxonomy($mf);
      }else{
        if($this->new_custom_taxonomy($mf)){
          //redirect to dashboard
        }else{
          //reload form and show warning
        }
      }
    }
    $this->mf_redirect(null,null,array('message' => 'success'));
  }