fix: extract labels to a separate contant

Author: Tomasz Los

google-cloud-bigquery/src/test/java/com/google/cloud/bigquery/BigQueryImplTest.java

@@ -132,6 +132,7 @@ public class BigQueryImplTest {
           .setField("timestampField");
   private static final TimePartitioning TIME_PARTITIONING_NULL_TYPE =
       TimePartitioning.fromPb(PB_TIMEPARTITIONING);
+  private static final ImmutableMap<String, String> LABELS = ImmutableMap.of("key", "value");
   private static final StandardTableDefinition TABLE_DEFINITION_WITH_PARTITIONING =
       StandardTableDefinition.newBuilder()
           .setSchema(TABLE_SCHEMA)
@@ -156,7 +157,7 @@ public class BigQueryImplTest {
   private static final TableInfo TABLE_INFO = TableInfo.of(TABLE_ID, TABLE_DEFINITION);
   private static final TableInfo OTHER_TABLE_INFO = TableInfo.of(OTHER_TABLE_ID, TABLE_DEFINITION);
   private static final TableInfo OTHER_TABLE_WITH_LABELS_INFO = TableInfo.newBuilder(OTHER_TABLE_ID, TABLE_DEFINITION)
-      .setLabels(ImmutableMap.of("key", "value"))
+      .setLabels(LABELS)
       .build();
   private static final TableInfo TABLE_INFO_WITH_PROJECT =
       TableInfo.of(TABLE_ID_WITH_PROJECT, TABLE_DEFINITION);
@@ -1168,7 +1169,7 @@ public void testListTablesWithLabels() throws IOException {
     assertEquals(CURSOR, page.getNextPageToken());
     assertArrayEquals(tableList.toArray(), Iterables.toArray(page.getValues(), Table.class));
     verify(bigqueryRpcMock).listTablesSkipExceptionTranslation(PROJECT, DATASET, EMPTY_RPC_OPTIONS);
-    assertEquals(ImmutableMap.of("key", "value"), page.getValues().iterator().next().getLabels());
+    assertEquals(LABELS, page.getValues().iterator().next().getLabels());
   }
 
   @Test