diff --git a/src/main/java/ab1/impl/GRUPPE/Tuple.java b/src/main/java/ab1/impl/GRUPPE/Tuple.java
deleted file mode 100644
index 50408cc..0000000
--- a/src/main/java/ab1/impl/GRUPPE/Tuple.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package ab1.impl.GRUPPE;
-
-public class Tuple {
-    private Character element_1;
-
-    public Character getElement_1() {
-        return element_1;
-    }
-
-    public void setElement_1(Character element_1) {
-        this.element_1 = element_1;
-    }
-
-    public String getElement_2() {
-        return element_2;
-    }
-
-    public void setElement_2(String element_2) {
-        this.element_2 = element_2;
-    }
-
-    private String element_2;
-
-
-
-    public Tuple(Character firstElement, String secondElement){
-        this.element_1=firstElement;
-        this.element_2=secondElement;
-    }
-}
diff --git a/src/main/java/ab1/impl/GRUPPE/NFAFactoryImpl.java b/src/main/java/ab1/impl/gruppe10_aigensberger_dworski_walcher/NFAFactoryImpl.java
similarity index 61%
rename from src/main/java/ab1/impl/GRUPPE/NFAFactoryImpl.java
rename to src/main/java/ab1/impl/gruppe10_aigensberger_dworski_walcher/NFAFactoryImpl.java
index ba6743a..78e09c8 100644
--- a/src/main/java/ab1/impl/GRUPPE/NFAFactoryImpl.java
+++ b/src/main/java/ab1/impl/gruppe10_aigensberger_dworski_walcher/NFAFactoryImpl.java
@@ -1,4 +1,4 @@
-package ab1.impl.GRUPPE;
+package ab1.impl.gruppe10_aigensberger_dworski_walcher;
 
 import ab1.NFA;
 import ab1.NFAFactory;
@@ -6,6 +6,9 @@ import ab1.NFAFactory;
 public class NFAFactoryImpl implements NFAFactory {
     @Override
     public NFA buildNFA(String startState) {
+        if (startState == null) {
+            return null;
+        }
         return new NFAImpl(startState);
     }
 }
diff --git a/src/main/java/ab1/impl/gruppe10_aigensberger_dworski_walcher/Tuple.java b/src/main/java/ab1/impl/gruppe10_aigensberger_dworski_walcher/Tuple.java
new file mode 100644
index 0000000..4dff076
--- /dev/null
+++ b/src/main/java/ab1/impl/gruppe10_aigensberger_dworski_walcher/Tuple.java
@@ -0,0 +1,14 @@
+package ab1.impl.gruppe10_aigensberger_dworski_walcher;
+
+import lombok.Getter;
+
+@Getter
+public class Tuple {
+    private final Character element_1;
+    private final String element_2;
+
+    public Tuple(Character firstElement, String secondElement){
+        this.element_1=firstElement;
+        this.element_2=secondElement;
+    }
+}
diff --git a/src/test/java/ab1/NFAProvider.java b/src/test/java/ab1/NFAProvider.java
index 35a3994..cc26c68 100644
--- a/src/test/java/ab1/NFAProvider.java
+++ b/src/test/java/ab1/NFAProvider.java
@@ -1,6 +1,6 @@
 package ab1;
 
-import ab1.impl.GRUPPE.NFAFactoryImpl;
+import ab1.impl.gruppe10_aigensberger_dworski_walcher.NFAFactoryImpl;
 
 public class NFAProvider {
     public static NFAFactory provideFactory() {
diff --git a/src/test/java/ab1/tests/GRUPPE/betterSimpleTests.java b/src/test/java/ab1/tests/GRUPPE/betterSimpleTests.java
new file mode 100644
index 0000000..b529cec
--- /dev/null
+++ b/src/test/java/ab1/tests/GRUPPE/betterSimpleTests.java
@@ -0,0 +1,76 @@
+package ab1.tests.GRUPPE;
+
+import ab1.NFAFactory;
+import ab1.NFAProvider;
+import ab1.Transition;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class betterSimpleTests {
+    private final NFAFactory factory = NFAProvider.provideFactory();
+    @Test
+    public void invalidInputTest() {
+        var instance = factory.buildNFA(null);
+        assertNull(instance);
+    }
+
+    @Test
+    public void invalidAcceptingState() {
+        var instance = factory.buildNFA("START");
+        instance.addAcceptingState(null);
+        assertEquals(0, instance.getAcceptingStates().size());
+    }
+
+    @Test
+    public void invalidTransition() {
+        var instance = factory.buildNFA("START");
+        assertThrows(IllegalArgumentException.class, () -> instance.addTransition(null));
+    }
+
+    @Test
+    public void transitionWithoutToState() {
+        var instance = factory.buildNFA("START");
+        Transition transition = ab1.Transition.builder()
+                .readSymbol('a')
+                .fromState("START")
+                .build();
+
+        assertThrows(IllegalArgumentException.class, () -> instance.addTransition(transition));
+    }
+
+
+    @Test
+    public void transitionWithoutExistingToState() {
+        var instance = factory.buildNFA("START");
+        instance.addTransition(
+                ab1.Transition.builder()
+                        .readSymbol('a')
+                        .fromState("START")
+                        .toState("END")
+                        .build()
+        );
+        assertEquals(1, instance.getTransitions().size());
+        assertEquals(2, instance.getStates().size());
+        assertEquals(0, instance.getAcceptingStates().size());
+    }
+
+    @Test
+    public void notInAlphabet(){
+        var instance = factory.buildNFA("START");
+        instance.addTransition(
+                ab1.Transition.builder()
+                        .readSymbol('a')
+                        .fromState("START")
+                        .toState("END")
+                        .build()
+        );
+        instance.addAcceptingState("END");
+        instance.finalizeAutomaton();
+
+        assertFalse(instance.acceptsWord("b"));
+        assertTrue(instance.acceptsWord("a"));
+        assertFalse(instance.acceptsWord("ab"));
+
+    }
+}
diff --git a/src/test/java/ab1/tests/myTests.java b/src/test/java/ab1/tests/GRUPPE/myTests.java
similarity index 98%
rename from src/test/java/ab1/tests/myTests.java
rename to src/test/java/ab1/tests/GRUPPE/myTests.java
index 3187091..aa169d5 100644
--- a/src/test/java/ab1/tests/myTests.java
+++ b/src/test/java/ab1/tests/GRUPPE/myTests.java
@@ -1,4 +1,4 @@
-package ab1.tests;
+package ab1.tests.GRUPPE;
 
 import ab1.NFA;
 import ab1.NFAFactory;