diff --git a/benchmark/src/main/java/net/woggioni/jwo/benchmark/Main.java b/benchmark/src/main/java/net/woggioni/jwo/benchmark/Main.java
index 8919a51..e42b27a 100644
--- a/benchmark/src/main/java/net/woggioni/jwo/benchmark/Main.java
+++ b/benchmark/src/main/java/net/woggioni/jwo/benchmark/Main.java
@@ -29,10 +29,10 @@ public class Main {
 
     public static void main(String... args)  {
         Map<String, Object> valuesMap = Stream.of(
-                new Tuple2<>("author", "John Doe"),
-                new Tuple2<>("date", "2020-03-25 16:22"),
-                new Tuple2<>("adjective", "simple"))
-            .collect(CollectionUtils.toUnmodifiableTreeMap(it -> it._1, it -> it._2));
+                Tuple2.newInstance("author", "John Doe"),
+                Tuple2.newInstance("date", "2020-03-25 16:22"),
+                Tuple2.newInstance("adjective", "simple"))
+            .collect(CollectionUtils.toUnmodifiableTreeMap(it -> it.get_1(), it -> it.get_2()));
         withBenchmarkReader(
                 reader -> {
                 Chronometer chronometer = new Chronometer();
diff --git a/src/main/java/net/woggioni/jwo/JWO.java b/src/main/java/net/woggioni/jwo/JWO.java
index 75f00ad..d0d4137 100644
--- a/src/main/java/net/woggioni/jwo/JWO.java
+++ b/src/main/java/net/woggioni/jwo/JWO.java
@@ -391,7 +391,7 @@ public class JWO {
             return Optional.empty();
         } else {
             return Optional.of(
-                    new Tuple2<>(fileName.substring(0, index), fileName.substring(index)));
+                    Tuple2.newInstance(fileName.substring(0, index), fileName.substring(index)));
         }
     }
 
diff --git a/src/main/java/net/woggioni/jwo/LazyValue.java b/src/main/java/net/woggioni/jwo/LazyValue.java
new file mode 100644
index 0000000..e92c066
--- /dev/null
+++ b/src/main/java/net/woggioni/jwo/LazyValue.java
@@ -0,0 +1,23 @@
+package net.woggioni.jwo;
+
+import java.util.function.Supplier;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+public class LazyValue<T> {
+    private final Supplier<T> valueSupplier;
+    private final MutableTuple2<T, Boolean> instance = MutableTuple2.newInstance(null, false);
+
+    public T get() {
+        if(instance.get_2()) return instance.get_1();
+        synchronized (instance) {
+            if(instance.get_2()) return instance.get_1();
+            else {
+                T value = valueSupplier.get();
+                instance.set_1(value);
+                instance.set_2(true);
+                return value;
+            }
+        }
+    }
+}
diff --git a/src/main/java/net/woggioni/jwo/MutableTuple2.java b/src/main/java/net/woggioni/jwo/MutableTuple2.java
index 53d4a9f..6ffb0cb 100644
--- a/src/main/java/net/woggioni/jwo/MutableTuple2.java
+++ b/src/main/java/net/woggioni/jwo/MutableTuple2.java
@@ -1,29 +1,12 @@
 package net.woggioni.jwo;
 
-import lombok.AllArgsConstructor;
-import lombok.EqualsAndHashCode;
-import lombok.NoArgsConstructor;
+import net.woggioni.jwo.internal.MutableTuple2Impl;
 
-import java.util.Comparator;
+public interface MutableTuple2<T, U> extends Tuple2<T, U> {
+    void set_1(T value);
+    void set_2(U value);
 
-@EqualsAndHashCode
-@NoArgsConstructor
-@AllArgsConstructor
-public class MutableTuple2<T, U> {
-    public T _1;
-    public U _2;
-
-    public static <X extends Comparable<X>, Y extends Comparable<Y>>
-    Comparator<MutableTuple2<X, Y>> getComparator(Class<X> cls1, Class<Y> cls2) {
-        return Comparator
-                .comparing((MutableTuple2<X, Y> t) -> t._1)
-                .thenComparing((MutableTuple2<X, Y> t) -> t._2);
-    }
-
-    public static <X extends Comparable<X>, Y extends Comparable<Y>>
-    Comparator<MutableTuple2<X, Y>> getComparator(MutableTuple2<X, Y> tuple) {
-        return Comparator
-                .comparing((MutableTuple2<X, Y> t) -> t._1)
-                .thenComparing((MutableTuple2<X, Y> t) -> t._2);
+    static <T,U> MutableTuple2<T, U> newInstance(T x, U y) {
+        return new MutableTuple2Impl<T, U>(x, y);
     }
 }
diff --git a/src/main/java/net/woggioni/jwo/MutableTuple3.java b/src/main/java/net/woggioni/jwo/MutableTuple3.java
index 1e44846..988777c 100644
--- a/src/main/java/net/woggioni/jwo/MutableTuple3.java
+++ b/src/main/java/net/woggioni/jwo/MutableTuple3.java
@@ -1,33 +1,14 @@
 package net.woggioni.jwo;
 
-import lombok.AllArgsConstructor;
-import lombok.EqualsAndHashCode;
-import lombok.NoArgsConstructor;
+import net.woggioni.jwo.internal.MutableTuple3Impl;
 
-import java.util.Comparator;
+public interface MutableTuple3<T, U, V> extends Tuple3<T, U , V> {
+    void set_1(T value);
+    void set_2(U value);
+    void set_3(V value);
 
-@EqualsAndHashCode
-@NoArgsConstructor
-@AllArgsConstructor
-public class MutableTuple3<T, U, V> {
-    public T _1;
-    public U _2;
-    public V _3;
-
-    public static <X extends Comparable<X>, Y extends Comparable<Y>, Z extends Comparable<Z>>
-    Comparator<MutableTuple3<X, Y, Z>> getComparator(Class<X> cls1, Class<Y> cls2, Class<Z> cls3) {
-        return Comparator
-                .comparing((MutableTuple3<X, Y, Z> t) -> t._1)
-                .thenComparing((MutableTuple3<X, Y, Z> t) -> t._2)
-                .thenComparing((MutableTuple3<X, Y, Z> t) -> t._3);
-    }
-
-    public static <X extends Comparable<X>, Y extends Comparable<Y>, Z extends Comparable<Z>>
-    Comparator<MutableTuple3<X, Y, Z>> getComparator(MutableTuple3<X, Y, Z> tuple) {
-        return Comparator
-                .comparing((MutableTuple3<X, Y, Z> t) -> t._1)
-                .thenComparing((MutableTuple3<X, Y, Z> t) -> t._2)
-                .thenComparing((MutableTuple3<X, Y, Z> t) -> t._3);
+    static <T, U, V> MutableTuple3<T, U, V> newInstance(T x, U y, V z) {
+        return new MutableTuple3Impl<>(x, y, z);
     }
 }
 
diff --git a/src/main/java/net/woggioni/jwo/Tuple2.java b/src/main/java/net/woggioni/jwo/Tuple2.java
index e5a951c..196fc71 100644
--- a/src/main/java/net/woggioni/jwo/Tuple2.java
+++ b/src/main/java/net/woggioni/jwo/Tuple2.java
@@ -1,25 +1,27 @@
 package net.woggioni.jwo;
 
-import lombok.EqualsAndHashCode;
-import lombok.RequiredArgsConstructor;
-
 import java.util.Comparator;
+import java.util.function.Function;
+import net.woggioni.jwo.internal.Tuple2Impl;
 
-@EqualsAndHashCode
-@RequiredArgsConstructor
-public class Tuple2<T, U> {
-    public final T _1;
-    public final U _2;
+public interface Tuple2<T, U> {
+    T get_1();
+    U get_2();
 
-    public static <X extends Comparable<X>, Y extends Comparable<Y>> Comparator<Tuple2<X, Y>> getComparator(Class<X> cls1, Class<Y> cls2) {
-        return Comparator
-            .comparing((Tuple2<X, Y> t) -> t._1)
-            .thenComparing((Tuple2<X, Y> t) -> t._2);
+    static <T,U> Tuple2<T, U> newInstance(T x, U y) {
+        return new Tuple2Impl<>(x, y);
     }
 
-    public static <X extends Comparable<X>, Y extends Comparable<Y>> Comparator<Tuple2<X, Y>> getComparator(Tuple2<X, Y> tuple) {
+    static <X extends Comparable<X>, Y extends Comparable<Y>> Comparator<Tuple2<X, Y>> getComparator(Class<X> cls1, Class<Y> cls2) {
         return Comparator
-                .comparing((Tuple2<X, Y> t) -> t._1)
-                .thenComparing((Tuple2<X, Y> t) -> t._2);
+                .comparing((Function<Tuple2<X, Y>, X>) Tuple2::get_1)
+                .thenComparing(Tuple2::get_2);
+    }
+
+    static <X extends Comparable<X>, Y extends Comparable<Y>> Comparator<Tuple2<X, Y>> getComparator(Tuple2<X, Y> tuple) {
+        return Comparator
+                .comparing((Function<Tuple2<X, Y>, X>) Tuple2::get_1)
+                .thenComparing(Tuple2::get_2);
     }
 }
+
diff --git a/src/main/java/net/woggioni/jwo/Tuple3.java b/src/main/java/net/woggioni/jwo/Tuple3.java
index a459563..ebc4889 100644
--- a/src/main/java/net/woggioni/jwo/Tuple3.java
+++ b/src/main/java/net/woggioni/jwo/Tuple3.java
@@ -1,30 +1,31 @@
 package net.woggioni.jwo;
 
-import lombok.EqualsAndHashCode;
-import lombok.RequiredArgsConstructor;
-
 import java.util.Comparator;
+import net.woggioni.jwo.internal.Tuple3Impl;
 
-@EqualsAndHashCode
-@RequiredArgsConstructor
-public class Tuple3<T, U, V> {
-    public final T _1;
-    public final U _2;
-    public final V _3;
+public interface Tuple3<T, U, V> {
+    T get_1();
+    U get_2();
+    V get_3();
 
-    public static <X extends Comparable<X>, Y extends Comparable<Y>, Z extends Comparable<Z>>
+    static <T, U, V> Tuple3<T, U, V> newInstance(T x, U y, V z) {
+        return new Tuple3Impl<>(x, y, z);
+    }
+
+    static <X extends Comparable<X>, Y extends Comparable<Y>, Z extends Comparable<Z>>
     Comparator<Tuple3<X, Y, Z>> getComparator(Class<X> cls1, Class<Y> cls2, Class<Z> cls3) {
         return Comparator
-            .comparing((Tuple3<X, Y, Z> t) -> t._1)
-            .thenComparing((Tuple3<X, Y, Z> t) -> t._2)
-            .thenComparing((Tuple3<X, Y, Z> t) -> t._3);
+                .comparing((Tuple3<X, Y, Z> t) -> t.get_1())
+                .thenComparing((Tuple3<X, Y, Z> t) -> t.get_2())
+                .thenComparing((Tuple3<X, Y, Z> t) -> t.get_3());
     }
 
-    public static <X extends Comparable<X>, Y extends Comparable<Y>, Z extends Comparable<Z>>
+    static <X extends Comparable<X>, Y extends Comparable<Y>, Z extends Comparable<Z>>
     Comparator<Tuple3<X, Y, Z>> getComparator(Tuple3<X, Y, Z> tuple) {
         return Comparator
-                .comparing((Tuple3<X, Y, Z> t) -> t._1)
-                .thenComparing((Tuple3<X, Y, Z> t) -> t._2)
-                .thenComparing((Tuple3<X, Y, Z> t) -> t._3);
+                .comparing((Tuple3<X, Y, Z> t) -> t.get_1())
+                .thenComparing((Tuple3<X, Y, Z> t) -> t.get_2())
+                .thenComparing((Tuple3<X, Y, Z> t) -> t.get_3());
     }
 }
+
diff --git a/src/main/java/net/woggioni/jwo/internal/MutableTuple2Impl.java b/src/main/java/net/woggioni/jwo/internal/MutableTuple2Impl.java
new file mode 100644
index 0000000..a63cbb6
--- /dev/null
+++ b/src/main/java/net/woggioni/jwo/internal/MutableTuple2Impl.java
@@ -0,0 +1,23 @@
+package net.woggioni.jwo.internal;
+
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import net.woggioni.jwo.MutableTuple2;
+
+@EqualsAndHashCode
+@NoArgsConstructor
+@AllArgsConstructor
+public class MutableTuple2Impl<T, U> implements MutableTuple2<T, U> {
+    @Getter
+    @Setter
+    private T _1;
+
+
+
+    @Getter
+    @Setter
+    private U _2;
+}
\ No newline at end of file
diff --git a/src/main/java/net/woggioni/jwo/internal/MutableTuple3Impl.java b/src/main/java/net/woggioni/jwo/internal/MutableTuple3Impl.java
new file mode 100644
index 0000000..29b11fc
--- /dev/null
+++ b/src/main/java/net/woggioni/jwo/internal/MutableTuple3Impl.java
@@ -0,0 +1,25 @@
+package net.woggioni.jwo.internal;
+
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import net.woggioni.jwo.MutableTuple3;
+
+@EqualsAndHashCode
+@NoArgsConstructor
+@AllArgsConstructor
+public class MutableTuple3Impl<T, U, V> implements MutableTuple3<T, U, V> {
+    @Getter
+    @Setter
+    private T _1;
+
+    @Getter
+    @Setter
+    private U _2;
+
+    @Getter
+    @Setter
+    private V _3;
+}
\ No newline at end of file
diff --git a/src/main/java/net/woggioni/jwo/internal/Tuple2Impl.java b/src/main/java/net/woggioni/jwo/internal/Tuple2Impl.java
new file mode 100644
index 0000000..778c7f1
--- /dev/null
+++ b/src/main/java/net/woggioni/jwo/internal/Tuple2Impl.java
@@ -0,0 +1,17 @@
+package net.woggioni.jwo.internal;
+
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import net.woggioni.jwo.Tuple2;
+
+@EqualsAndHashCode
+@RequiredArgsConstructor
+public class Tuple2Impl<T, U> implements Tuple2<T, U> {
+    @Getter
+    private final T _1;
+
+    @Getter
+    private  final U _2;
+}
+
diff --git a/src/main/java/net/woggioni/jwo/internal/Tuple3Impl.java b/src/main/java/net/woggioni/jwo/internal/Tuple3Impl.java
new file mode 100644
index 0000000..739965f
--- /dev/null
+++ b/src/main/java/net/woggioni/jwo/internal/Tuple3Impl.java
@@ -0,0 +1,11 @@
+package net.woggioni.jwo.internal;
+
+import lombok.Data;
+import net.woggioni.jwo.Tuple3;
+
+@Data
+public class Tuple3Impl<T, U, V> implements Tuple3<T, U, V> {
+    private final T _1;
+    private final U _2;
+    private final V _3;
+}
diff --git a/src/test/java/net/woggioni/jwo/TreeWalkerTest.java b/src/test/java/net/woggioni/jwo/TreeWalkerTest.java
index 1c44f9a..294b78c 100644
--- a/src/test/java/net/woggioni/jwo/TreeWalkerTest.java
+++ b/src/test/java/net/woggioni/jwo/TreeWalkerTest.java
@@ -27,14 +27,14 @@ public class TreeWalkerTest {
 
     private Map<Integer, List<Integer>> parentChildRelationshipMap =
             Stream.of(
-                    new Tuple2<>(1, Collections.singletonList(2)),
-                    new Tuple2<>(2, Collections.singletonList(3)),
-                    new Tuple2<>(3, Arrays.asList(4, 5)),
-                    new Tuple2<>(4, Arrays.asList(6, 7)),
-                    new Tuple2<>(5, Collections.singletonList(8))
-            ).collect(Collectors.toMap(t -> t._1, t -> t._2));
+                    Tuple2.newInstance(1, Collections.singletonList(2)),
+                    Tuple2.newInstance(2, Collections.singletonList(3)),
+                    Tuple2.newInstance(3, Arrays.asList(4, 5)),
+                    Tuple2.newInstance(4, Arrays.asList(6, 7)),
+                    Tuple2.newInstance(5, Collections.singletonList(8))
+            ).collect(Collectors.toMap(Tuple2::get_1, Tuple2::get_2));
 
-    private Map<Integer, Node> testNodeMap = parentChildRelationshipMap.entrySet().stream()
+    private final Map<Integer, Node> testNodeMap = parentChildRelationshipMap.entrySet().stream()
             .map(entry -> newNode(entry.getKey(), entry.getValue()))
             .collect(Collectors.toMap(Node::getId, Function.identity()));