Whitelist ConcurrentHashMap#initTable (#34)

* Whitelist `ConcurrentHashMap#initTable`

* Add the license header

agent/src/main/java/reactor/blockhound/BlockHound.java

@@ -30,6 +30,7 @@
 import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
 import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Consumer;
 import java.util.function.Function;
@@ -148,6 +149,10 @@ public static class Builder {
             put(Throwable.class, new HashMap<String, Boolean>() {{
                 put("printStackTrace", true);
             }});
+
+            put(ConcurrentHashMap.class, new HashMap<String, Boolean>() {{
+                put("initTable", true);
+            }});
         }};
 
         private Consumer<BlockingMethod> onBlockingMethod = method -> {

example/src/test/java/com/example/JDKTest.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2019-Present Pivotal Software Inc, All Rights Reserved.
+ *
+ * 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
+ *
+ *       https://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 com.example;
+
+import org.junit.Test;
+import reactor.blockhound.BlockHound;
+import reactor.core.publisher.Flux;
+import reactor.core.scheduler.Schedulers;
+
+import java.util.concurrent.ConcurrentHashMap;
+
+public class JDKTest {
+
+    static {
+        BlockHound.install();
+    }
+
+    @Test
+    public void shouldAllowConcurrentHashMapInit() {
+        for (int i = 0; i < 100; i++) {
+            var map = new ConcurrentHashMap<Integer, Boolean>();
+            Flux.range(0, Runtime.getRuntime().availableProcessors())
+                    .parallel()
+                    .runOn(Schedulers.parallel())
+                    .doOnNext(it -> map.put(it, true))
+                    .sequential()
+                    .blockLast();
+        }
+    }
+}