public function update_visibility($visible = null) {
        if (is_bool($visible)) {
            $this->_visible = $visible;
        } else {
            $this->_visible = !$this->_visible;
        }
        return $this->update_visible();
    }
public function update_visibility($visible = null) {
        if (is_bool($visible)) {
            $this->_visible = $visible;
        } else {
            $this->_visible = !$this->_visible;
        }
        return $this->update_visible();
    }
public function update_visibility ( $ visible = null ) { if ( is_bool ( $ visible ) ) { $ this -> _visible = $ visible ; } else { $ this -> _visible = ! $ this -> _visible ; } return $ this -> update_visible ( ) ; }
1. Change visibility to the value chosen
2. Update the type

@param bool $visible
@return bool
1 . Change visibility to the value chosen 2 . Update the type