diff --git a/feature-toggle/src/main/java/com/iluwatar/featuretoggle/user/UserGroup.java b/feature-toggle/src/main/java/com/iluwatar/featuretoggle/user/UserGroup.java
index 1328afbc8..d3052ac21 100644
--- a/feature-toggle/src/main/java/com/iluwatar/featuretoggle/user/UserGroup.java
+++ b/feature-toggle/src/main/java/com/iluwatar/featuretoggle/user/UserGroup.java
@@ -11,6 +11,7 @@ public class UserGroup {
   private static List<User> freeGroup = new ArrayList<>();
   private static List<User> paidGroup = new ArrayList<>();
 
+
   /**
    *
    * @param user {@link User} to be added to the free group
diff --git a/feature-toggle/src/test/java/com/iluwatar/featuretoggle/pattern/propertiesversion/PropertiesFeatureToggleVersionTest.java b/feature-toggle/src/test/java/com/iluwatar/featuretoggle/pattern/propertiesversion/PropertiesFeatureToggleVersionTest.java
index 7a07193c8..714eb5070 100644
--- a/feature-toggle/src/test/java/com/iluwatar/featuretoggle/pattern/propertiesversion/PropertiesFeatureToggleVersionTest.java
+++ b/feature-toggle/src/test/java/com/iluwatar/featuretoggle/pattern/propertiesversion/PropertiesFeatureToggleVersionTest.java
@@ -13,6 +13,18 @@ import static org.junit.Assert.assertTrue;
 
 public class PropertiesFeatureToggleVersionTest {
 
+  @Test(expected = IllegalArgumentException.class)
+  public void testNullPropertiesPassed() throws Exception {
+    new PropertiesFeatureToggleVersion(null);
+  }
+
+  @Test(expected = IllegalArgumentException.class)
+  public void testNonBooleanProperty() throws Exception {
+    final Properties properties = new Properties();
+    properties.setProperty("enhancedWelcome","Something");
+    new PropertiesFeatureToggleVersion(properties);
+  }
+
   @Test
   public void testFeatureTurnedOn() throws Exception {
     final Properties properties = new Properties();