Add toString override and remove setValue

Author: yashshah03

DataStructures/Graph/src/graph/Node.java

@@ -12,7 +12,9 @@ public Node(String value)
     {
         this.value = value;
     }
+   
+    public String getValue() { return this.value; }
 
-    public void setValue(String value) { this.value = value; }
-    public String getValue() { return value; }
+    @Override
+    public String toString() { return this.value; }
 }