Github user cestella commented on a diff in the pull request:
https://github.com/apache/metron/pull/1021#discussion_r189895940
--- Diff:
metron-stellar/stellar-common/src/main/java/org/apache/metron/stellar/common/utils/ConcatMap.java
---
@@ -0,0 +1,202 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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 org.apache.metron.stellar.common.utils;
+
+
+import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.KryoSerializable;
+import com.esotericsoftware.kryo.io.Input;
+import com.esotericsoftware.kryo.io.Output;
+import com.google.common.base.Joiner;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Sets;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
--- End diff --
Yep, absolutely.
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