### Question:
NetworkUsageMetricsCollector { void addRxBytes(long bytes) { metrics.addRxBytesForType(getActiveNetworkType(), bytes); } NetworkUsageMetricsCollector(Context context, TelemetryMetrics metrics);   }### Answer:
@Test public void addRxBytes() { networkUsageMetricsCollector.addRxBytes(30); verify(metrics).addRxBytesForType(anyInt(), anyLong()); }