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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def send_heartbeat(self):
        '''
        Send a heartbeat if needed. Tracks last heartbeat send time.
        '''
        # Note that this does not take into account the time that we last
        # sent a frame. Hearbeats are so small the effect should be quite
        # limited. Also note that we're looking for something near to our
        # scheduled interval, because if this is exact, then we'll likely
        # actually send a heartbeat at twice the period, which could cause
        # a broker to kill the connection if the period is large enough. The
        # 90% bound is arbitrary but seems a sensible enough default.
        if self.connection._heartbeat:
            if time.time() >= (self._last_heartbeat_send + 0.9 *
                               self.connection._heartbeat):
                self.send_frame(HeartbeatFrame(self.channel_id))
                self._last_heartbeat_send = time.time()