Added a test case to verify multi-level additional data setter and added a comment to explain the IllegalArgumentException

Author: FAREAST\vidadhee

src/main/java/com/microsoft/graph/serializer/DefaultSerializer.java

@@ -148,7 +148,8 @@ else if (fieldObject != null && fieldObject instanceof IJsonBackedObject) {
                     setChildAdditionalData((IJsonBackedObject) fieldObject,rawJson.get(field.getName()).getAsJsonObject());
                 }
             } catch (IllegalArgumentException | IllegalAccessException e) {
-                logger.logError("Unable to access child fields of " + serializedObject.getClass().getSimpleName(), e);
+                //Not throwing the IllegalArgumentException as the Serialized Object would still be usable even if the additional data is not set.
+                logger.logError("Unable to set child fields of " + serializedObject.getClass().getSimpleName(), e);
             }
         }
     }

src/test/java/com/microsoft/graph/serializer/AdditionalDataTests.java

@@ -5,8 +5,10 @@
 import org.junit.Before;
 import org.junit.Test;
 
+import com.google.gson.JsonElement;
 import com.google.gson.JsonPrimitive;
 import com.microsoft.graph.logger.DefaultLogger;
+import com.microsoft.graph.models.extensions.Drive;
 import com.microsoft.graph.models.extensions.Entity;
 import com.microsoft.graph.models.extensions.PlannerAssignment;
 import com.microsoft.graph.models.extensions.PlannerAssignments;
@@ -48,6 +50,15 @@ public void testChildAdditionalData() {
 
 		assertEquals("{\"manager\":{\"id\":\"1\",\"additionalData\":\"additionalValue\"},\"id\":\"2\"}", serializedObject);
 	}
+
+	@Test
+	public void testChildAdditionalDataDeserialization() {
+		String source = "{\"@odata.context\":\"https://graph.microsoft.com/v1.0/$metadata#drives/$entity\",\"id\":\"8bf6ae90006c4a4c\",\"driveType\":\"personal\",\"owner\":{\"user\":{\"displayName\":\"Peter\",\"id\":\"8bf6ae90006c4a4c\",\"email\":\"[email protected]\"}},\"quota\":{\"deleted\":1485718314,\"remaining\":983887466461,\"state\":\"normal\",\"total\":1142461300736,\"used\":158573834275}}";
+		Drive result = serializer.deserializeObject(source, Drive.class);
+		JsonElement email = result.owner.user.additionalDataManager().get("email");
+
+		assertEquals("\"[email protected]\"",email.toString());
+	}
 
 	@Test
 	public void testSkipTransientData() {