Workaround #6824 for J2KT test

RELNOTES=n/a
PiperOrigin-RevId: 610746438

Author: martinkretzschmar

guava-tests/test/com/google/common/collect/TableCollectorsTest.java

@@ -25,9 +25,11 @@
 import com.google.common.collect.Table.Cell;
 import com.google.common.testing.CollectorTester;
 import java.util.function.BiPredicate;
+import java.util.function.BinaryOperator;
 import java.util.stream.Collector;
 import java.util.stream.Stream;
 import junit.framework.TestCase;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 /** Unit tests for {@link TableCollectors}. */
 @GwtCompatible(emulated = true)
@@ -191,12 +193,15 @@ public void testToTable() {
   }
 
   public void testToTableNullMerge() {
+    // TODO github.com/google/guava/issues/6824 - the null merge feature is not compatible with the
+    // current nullness annotation of the mergeFunction parameter. Work around with casts.
+    BinaryOperator<@Nullable Integer> mergeFunction = (v1, v2) -> null;
     Collector<Cell<String, String, Integer>, ?, Table<String, String, Integer>> collector =
         TableCollectors.toTable(
             Cell::getRowKey,
             Cell::getColumnKey,
             Cell::getValue,
-            (Integer v1, Integer v2) -> null,
+            (BinaryOperator<Integer>) mergeFunction,
             HashBasedTable::create);
     BiPredicate<Table<String, String, Integer>, Table<String, String, Integer>> equivalence =
         pairwiseOnResultOf(Table::cellSet);