TestTreeApp.java

package tree;

import java.util.TreeMap;

public class TestTreeApp {

	public static void main(String[] args) {
		TreeMap<String, String> map = new TreeMap<String, String>();
		map.put("2", "");
		map.put("1", "");
		// map.put("3", "");
		map.remove("2");
	}

}