Automatic code cleanup.

PiperOrigin-RevId: 438299221
diff --git a/src/main/java/com/google/devtools/build/lib/metrics/BUILD b/src/main/java/com/google/devtools/build/lib/metrics/BUILD
index f0e3e9e..6cdc547 100644
--- a/src/main/java/com/google/devtools/build/lib/metrics/BUILD
+++ b/src/main/java/com/google/devtools/build/lib/metrics/BUILD
@@ -46,6 +46,7 @@
         "//src/main/java/com/google/devtools/build/lib/worker",
         "//src/main/java/com/google/devtools/build/skyframe:skyframe_graph_stats_event",
         "//src/main/java/com/google/devtools/common/options",
+        "//third_party:error_prone_annotations",
         "//third_party:guava",
     ],
 )
diff --git a/src/main/java/com/google/devtools/build/lib/metrics/MetricsCollector.java b/src/main/java/com/google/devtools/build/lib/metrics/MetricsCollector.java
index 1bb15f7..e206943 100644
--- a/src/main/java/com/google/devtools/build/lib/metrics/MetricsCollector.java
+++ b/src/main/java/com/google/devtools/build/lib/metrics/MetricsCollector.java
@@ -51,6 +51,7 @@
 import com.google.devtools.build.lib.worker.WorkerMetric;
 import com.google.devtools.build.lib.worker.WorkerMetricsEvent;
 import com.google.devtools.build.skyframe.SkyframeGraphStatsEvent;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Comparator;
@@ -95,6 +96,7 @@
   private final List<WorkerMetrics> workerMetricsList = new ArrayList<>();
   private final SpawnStats spawnStats = new SpawnStats();
 
+  @CanIgnoreReturnValue
   private MetricsCollector(
       CommandEnvironment env, AtomicInteger numAnalyses, AtomicInteger numBuilds) {
     this.env = env;