Add tests

modules/runner/src/integrationTest/java/org/apache/ignite/internal/table/ItDurableFinishTest.java

@@ -66,7 +66,6 @@
 import org.apache.ignite.table.Tuple;
 import org.apache.ignite.tx.MismatchingTransactionOutcomeException;
 import org.apache.ignite.tx.TransactionException;
-import org.jetbrains.annotations.Nullable;
 import org.junit.jupiter.api.Test;
 
 /**
@@ -383,16 +382,6 @@ void testCleanupReplicatedMessage() throws ExecutionException, InterruptedExcept
         );
     }
 
-    private @Nullable Integer nodeIndex(String name) {
-        for (int i = 0; i < initialNodes(); i++) {
-            if (node(i).name().equals(name)) {
-                return i;
-            }
-        }
-
-        return null;
-    }
-
     private static class Context {
         private final IgniteImpl primaryNode;
         private final IgniteImpl coordinatorNode;

modules/runner/src/testFixtures/java/org/apache/ignite/internal/Cluster.java

@@ -357,6 +357,13 @@ public Ignite node(int index) {
         return Objects.requireNonNull(nodes.get(index));
     }
 
+    /**
+     * Returns an Ignite node (a member of the cluster) by its index.
+     */
+    public @Nullable Ignite nullableNode(int index) {
+        return nodes.get(index);
+    }
+
     /**
      * Returns a node that is not stopped and not knocked out (so it can be used to interact with the cluster).
      */

modules/runner/src/testFixtures/java/org/apache/ignite/internal/ClusterPerTestIntegrationTest.java

@@ -34,6 +34,7 @@
 import org.apache.ignite.internal.testframework.BaseIgniteAbstractTest;
 import org.apache.ignite.internal.testframework.WorkDirectory;
 import org.apache.ignite.internal.testframework.WorkDirectoryExtension;
+import org.jetbrains.annotations.Nullable;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.TestInfo;
@@ -220,6 +221,14 @@ protected final Ignite node(int index) {
         return cluster.node(index);
     }
 
+    public @Nullable Ignite nullableNode(int index) {
+        return cluster.nullableNode(index);
+    }
+
+    protected int nodeIndex(String name) {
+        return cluster.nodeIndex(name);
+    }
+
     protected final IgniteImpl igniteImpl(int index) {
         return unwrapIgniteImpl(node(index));
     }