private function createLockFile($content = null)
    {
        if ($this->lockFile) {
            if ($content === null || ! is_string($content)) {
                $content = $this->getId();
            }

            file_put_contents($this->lockFile, $content);
        }
    }
private function createLockFile($content = null)
    {
        if ($this->lockFile) {
            if ($content === null || ! is_string($content)) {
                $content = $this->getId();
            }

            file_put_contents($this->lockFile, $content);
        }
    }
private function createLockFile ( $ content = null ) { if ( $ this -> lockFile ) { if ( $ content === null || ! is_string ( $ content ) ) { $ content = $ this -> getId ( ) ; } file_put_contents ( $ this -> lockFile , $ content ) ; } }
Create the job lock file.

@param  mixed  $content
@return void
Create the job lock file .