TreeMap remove(Object key) method in java

import java.util.TreeMap;
public class TreeMapRemoveMethodExample
{
   public static void main(String[] args)
   {
      TreeMap<Integer, String> tm = new TreeMap<Integer, String>();
      tm.put(32, "pineapple");
      tm.put(51, "watermelon");
      tm.put(38, "grapes");
      tm.put(69, "mango");
      tm.put(58, "apple");
      System.out.println("Given TreeMap is: " + tm);
      // remove existing key mapping
      String strReturn = (String)tm.remove(38);
      System.out.println("Returned value is: " + strReturn);
      System.out.println("New TreeMap is: " + tm);
   }
}