Completed AtlanmodHandshake tests

examples/src/test/java/comparisons/handshakes/AtlanmodHandshake.java

 package comparisons.handshakes;
 
+import org.apache.commons.lang3.Validate;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.examples.BiDirectionalAssociation;
+import org.atlanmod.commons.Guards;
+
+import java.security.Guard;
+
 public class AtlanmodHandshake {
+    private BiDirectionalAssociation<Integer> BDA_0;
+    private BiDirectionalAssociation<Integer> BDA_1;
+    private BiDirectionalAssociation<Integer> BDA_2;
+    private BiDirectionalAssociation<Integer> BDA_3;
+
+    @BeforeEach
+    public void setup()
+    {
+        BDA_0 = new BiDirectionalAssociation<>();
+        BDA_1 = new BiDirectionalAssociation<>();
+        BDA_2 = new BiDirectionalAssociation<>();
+        BDA_3 = new BiDirectionalAssociation<>();
+
+    }
+
+    @Test
+    public void testSet()
+    {
+        //test all get() is null
+        Guards.checkEqualTo(BDA_0.get(), null);
+        Guards.checkEqualTo(BDA_1.get(), null);
+        Guards.checkEqualTo(BDA_2.get(), null);
+        Guards.checkEqualTo(BDA_3.get(), null);
+
+
+        BDA_0.set(BDA_1);
+
+        //test bda_0 & bda_1 associated
+        Guards.checkEqualTo(BDA_0.get(), BDA_1);
+        Guards.checkEqualTo(BDA_1.get(), BDA_0);
+
+
+        BDA_1.set(BDA_2);
+
+        //test bda_0 is null
+        Guards.checkEqualTo(BDA_0.get(), null);
+
+        //test bda_2 & bda_1 linked
+        Guards.checkEqualTo(BDA_1.get(), BDA_2);
+        Guards.checkEqualTo(BDA_2.get(), BDA_1);
+
+        BDA_3.set(BDA_0);
+
+        //test bda_3 & bda_0 linked
+        Guards.checkEqualTo(BDA_0.get(), BDA_3);
+        Guards.checkEqualTo(BDA_3.get(), BDA_0);
+    }
+
+    @Test
+    public void testUnSet()
+    {
+        BDA_0.set(BDA_1);
+        BDA_2.set(BDA_3);
+
+        //test all is not get() null
+        Guards.checkNotNull(BDA_0.get());
+        Guards.checkNotNull(BDA_1.get());
+        Guards.checkNotNull(BDA_2.get());
+        Guards.checkNotNull(BDA_3.get());
+
+
+        BDA_3.unSet();
+
+        //test BDA-3 & BDA_2 get() null
+        Guards.checkEqualTo(BDA_2.get(), null);
+        Guards.checkEqualTo(BDA_3.get(), null);
+
+        BDA_0.unSet();
+
+        //test bda_0 & bda_1 get() null
+        Guards.checkEqualTo(BDA_0.get(), null);
+        Guards.checkEqualTo(BDA_1.get(), null);
+
+
+
+    }
 }