public function write($content = '')
    {
        if ($this->rotate()) {
            if (empty($this->file_mtime) && file_exists($this->file_path)) {
                $this->file_mtime = filemtime($this->file_path);
            }
            $f = @fopen($this->file_path, "ab");
            if ($f) {
                fputs($f, str_replace('<', '&lt;', $content));
                fclose($f);
                $this->file_mtime = filemtime($this->file_path);
                return true;
            } else {
                throw new \RuntimeException(
                    sprintf('Can not write in file "%s"!', $this->file_path)
                );
            }
        } else {
            throw new \RuntimeException(
                sprintf('Can not write and/or rotate file "%s"!', $this->file_path)
            );
        }
    }