[PAN-2822] AllNodesVisitorTest (#1831)

* AllNodesVisitorTest

ethereum/trie/src/main/java/tech/pegasys/pantheon/ethereum/trie/AllNodesVisitor.java

@@ -31,9 +31,7 @@ public void visit(final ExtensionNode<V> extensionNode) {
   @Override
   public void visit(final BranchNode<V> branchNode) {
     handler.accept(branchNode);
-    for (byte i = 0; i < BranchNode.RADIX; i++) {
-      acceptAndUnload(branchNode.child(i));
-    }
+    branchNode.getChildren().forEach(this::acceptAndUnload);
   }
 
   @Override

ethereum/trie/src/test/java/tech/pegasys/pantheon/ethereum/trie/AllNodesVisitorTest.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2019 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.ethereum.trie;
+
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.util.Collections;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+@RunWith(MockitoJUnitRunner.class)
+public class AllNodesVisitorTest {
+
+  @Mock private StoredNode<String> storedNode;
+  @Mock private ExtensionNode<String> extensionNode;
+  @Mock private BranchNode<String> branchNode;
+
+  @Test
+  public void visitExtension() {
+    when(extensionNode.getChild()).thenReturn(storedNode);
+    new AllNodesVisitor<String>(x -> {}).visit(extensionNode);
+    verify(storedNode).unload();
+  }
+
+  @Test
+  public void visitBranch() {
+    when(branchNode.getChildren()).thenReturn(Collections.singletonList(storedNode));
+    new AllNodesVisitor<String>(x -> {}).visit(branchNode);
+    verify(storedNode).unload();
+  }
+}