refactor

school/Manager.java

@@ -0,0 +1,24 @@
+package school;
+
+public class Manager extends Person {
+    private static Manager instance = null;
+
+    private Manager(String name, int age) {
+        super(name, age);
+    }
+
+    public static Manager getInstance(String name, int age) {
+        if (instance == null) {
+            instance = new Manager(name, age);
+        }
+        return instance;
+    }
+
+    public void manage() {
+        System.out.println("I am the administrator and I am responsible for managing everyone.");
+    }
+
+    public void speak() {
+        System.out.println("I am the manager, my name is " + getName() + ", and I am " + getAge() + " years old.");
+    }
+}