<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def Heartbeat(self):
 """Writes a heartbeat to the registry."""

    service_key = _GetServiceKey()
    try:
      winreg.SetValueEx(service_key, "Nanny.heartbeat", 0, winreg.REG_DWORD,
                        int(time.time()))
    except OSError as e:
      logging.debug("Failed to heartbeat nanny at %s: %s", service_key, e)