diff --git a/core-java-collections/src/test/java/com/baeldung/java/map/KeyCheckTest.java b/core-java-collections/src/test/java/com/baeldung/java/map/KeyCheckTest.java
new file mode 100644
index 0000000000..024b2973d2
--- /dev/null
+++ b/core-java-collections/src/test/java/com/baeldung/java/map/KeyCheckTest.java
@@ -0,0 +1,44 @@
+package com.baeldung.java.map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.commons.collections4.MultiMap;
+import org.apache.commons.collections4.MultiMapUtils;
+import org.apache.commons.collections4.MultiValuedMap;
+import org.apache.commons.collections4.map.MultiValueMap;
+import org.apache.commons.collections4.multimap.ArrayListValuedHashMap;
+import org.apache.commons.collections4.multimap.HashSetValuedHashMap;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.collect.ArrayListMultimap;
+import com.google.common.collect.LinkedHashMultimap;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.TreeMultimap;
+
+
+public class KeyCheckTest {
+
+    @Test
+    public void whenKeyIsPresent_thenContainsKeyReturnsTrue() {
+        Map<String, String> map = Collections.singletonMap("key", "value");
+
+        assertTrue(map.containsKey("key"));
+        assertFalse(map.containsKey("missing"));
+    }
+
+    @Test
+    public void whenKeyHasNullValue_thenGetStillWorks() {
+        Map<String, String> map = Collections.singletonMap("nothing", null);
+
+        assertTrue(map.containsKey("nothing"));
+        assertNull(map.get("nothing"));
+    }
+}
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