<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def collect(self):
 """ Collects all metrics attached to this metricset, and returns it as a list, together with a timestamp in microsecond precision. The format of the return value should be { "timestamp": unix epoch in microsecond precision } """

        samples = {}
        if self._counters:
            samples.update(
                {label: {"value": c.val} for label, c in compat.iteritems(self._counters) if c is not noop_metric}
            )
        if self._gauges:
            samples.update(
                {label: {"value": g.val} for label, g in compat.iteritems(self._gauges) if g is not noop_metric}
            )
        if samples:
            return {"samples": samples, "timestamp": int(time.time() * 1000000)}