Merge pull request #14220 from thibaultfaure/article/BAEL-6482

BAEL-6482 Code for the Matching Null With Mockito article

testing-modules/mockito-2/src/main/java/com/baeldung/nullmatcher/Helper.java

@@ -0,0 +1,9 @@
+package com.baeldung.nullmatcher;
+
+class Helper {
+
+    String concat(String a, String b) {
+        return a + b;
+    }
+
+}

testing-modules/mockito-2/src/main/java/com/baeldung/nullmatcher/Main.java

@@ -0,0 +1,11 @@
+package com.baeldung.nullmatcher;
+
+class Main {
+
+    Helper helper = new Helper();
+
+    String methodUnderTest() {
+        return helper.concat("Baeldung", null);
+    }
+
+}