code: public function stream_close()
      {
          if (!$this->handle) {
              return;
          }
          self::restorePrev();
          \fclose($this->handle);
          $this->handle = null;
          self::register();
      }
docs: Close a file
  
  @see http://php.net/manual/en/streamwrapper.stream-close.php
  
  @return void