fix checkstyle

Author: Abacn

runners/core-java/src/main/java/org/apache/beam/runners/core/metrics/BoundedTrieData.java

@@ -345,7 +345,8 @@ public BoundedTrieNode() {
      * @param truncated Whether this node is truncated.
      * @param size The size of the subtree rooted at this node.
      */
-    public BoundedTrieNode(@Nonnull Map<String, BoundedTrieNode> children, boolean truncated, int size) {
+    public BoundedTrieNode(
+        @Nonnull Map<String, BoundedTrieNode> children, boolean truncated, int size) {
       this.children = children;
       this.size = size;
       this.truncated = truncated;

runners/google-cloud-dataflow-java/src/main/java/org/apache/beam/runners/dataflow/DataflowMetrics.java

@@ -241,7 +241,7 @@ private DistributionResult getDistributionValue(MetricUpdate metricUpdate) {
 
     /** Translate Struct proto returned by Dataflow API client to BoundedTrieData. */
     @VisibleForTesting
-    @SuppressWarnings("ReferenceEquality") // compare with protobuf Struct default instance
+    @SuppressWarnings("ReferenceEquality") // Compare with protobuf Struct default instance
     static BoundedTrieData trieFromStruct(com.google.protobuf.Struct responseProto) {
       Map<String, com.google.protobuf.Value> fieldsMap = responseProto.getFieldsMap();
       int bound = 0;
@@ -271,7 +271,7 @@ static BoundedTrieData trieFromStruct(com.google.protobuf.Struct responseProto)
     /**
      * Translate Struct proto returned by Dataflow API client to BoundedTrieData.BoundedTrieNode.
      */
-    @SuppressWarnings("ReferenceEquality") // compare with protobuf Struct default instance
+    @SuppressWarnings({"ReferenceEquality"}) // Compare with protobuf Struct default instance
     private static BoundedTrieData.BoundedTrieNode trieNodeFromStruct(
         com.google.protobuf.Struct responseProto) {
       Map<String, com.google.protobuf.Value> fieldsMap = responseProto.getFieldsMap();

runners/google-cloud-dataflow-java/src/test/java/org/apache/beam/runners/dataflow/DataflowMetricsTest.java

@@ -39,7 +39,6 @@
 import com.google.api.services.dataflow.model.JobMetrics;
 import com.google.api.services.dataflow.model.MetricStructuredName;
 import com.google.api.services.dataflow.model.MetricUpdate;
-import com.google.protobuf.Struct;
 import com.google.protobuf.TextFormat;
 import com.google.protobuf.TextFormat.ParseException;
 import java.io.IOException;
@@ -328,7 +327,8 @@ public void testSingletonBoundedTrieFromMessage() throws ParseException {
             + "      }\n"
             + "    }\n"
             + "  }";
-    Struct response = TextFormat.parse(textProto, Struct.class);
+    com.google.protobuf.Struct response =
+        TextFormat.parse(textProto, com.google.protobuf.Struct.class);
     BoundedTrieData result = DataflowMetrics.DataflowMetricResultExtractor.trieFromStruct(response);
     assertEquals(
         "BoundedTrieData({'pubsub:topic:`google.com:abc`.some-topicfalse'})", result.toString());
@@ -416,7 +416,8 @@ public void testNestedBoundedTrieFromMessage() throws ParseException {
             + "    }\n"
             + "  }\n"
             + "}";
-    Struct response = TextFormat.parse(textProto, Struct.class);
+    com.google.protobuf.Struct response =
+        TextFormat.parse(textProto, com.google.protobuf.Struct.class);
     BoundedTrieData result = DataflowMetrics.DataflowMetricResultExtractor.trieFromStruct(response);
     assertEquals("BoundedTrieData({'gcs:some-bucket.some-folder/true'})", result.toString());
   }