<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def start(self):
 """Start the background process."""

        self._lc = LoopingCall(self._download)
        # Run immediately, and then every 30 seconds:
        self._lc.start(30, now=True)