def resume(self):
        """Resume process execution."""
        # safety measure in case the current process has been killed in
        # meantime and the kernel reused its PID
        if not self.is_running():
            name = self._platform_impl._process_name
            raise NoSuchProcess(self.pid, name)
        # windows
        if hasattr(self._platform_impl, "resume_process"):
            self._platform_impl.resume_process()
        else:
            # posix
            self.send_signal(signal.SIGCONT)
Resume process execution.