Add record is null smt

src/main/java/io/lenses/connect/smt/header/RecordIsNull.java

@@ -0,0 +1,45 @@
+package io.lenses.connect.smt.header;
+
+import org.apache.kafka.common.config.ConfigDef;
+import org.apache.kafka.common.utils.AppInfoParser;
+import org.apache.kafka.connect.components.Versioned;
+import org.apache.kafka.connect.connector.ConnectRecord;
+import org.apache.kafka.connect.transforms.predicates.Predicate;
+
+import java.util.Map;
+
+public class RecordIsNull<R extends ConnectRecord<R>> implements Predicate<R>, Versioned {
+
+    public static final String OVERVIEW_DOC = "A predicate which is true for records which are tombstones (i.e. have null value).";
+    public static final ConfigDef CONFIG_DEF = new ConfigDef();
+
+    @Override
+    public String version() {
+        return AppInfoParser.getVersion();
+    }
+
+    @Override
+    public ConfigDef config() {
+        return CONFIG_DEF;
+    }
+
+    @Override
+    public boolean test(R record) {
+        return record == null;
+    }
+
+    @Override
+    public void close() {
+
+    }
+
+    @Override
+    public void configure(Map<String, ?> configs) {
+
+    }
+
+    @Override
+    public String toString() {
+        return "RecordIsTombstone{}";
+    }
+}