This method for run some function at subprocess.
        Very useful when you have a problem with memory leaks.

def run_at_subprocess(self, use_subprocess, foo, *args, **kwrags):
        """
        This method for run some function at subprocess.
        Very useful when you have a problem with memory leaks.
        """
        if use_subprocess is False:
            return foo(*args, **kwrags)

        child_pid = os.fork()
        if child_pid == 0:
            foo(*args, **kwrags)
            sys.exit(0)
        return os.waitpid(child_pid, 0)[1] == 0