What is AbstractMap clear() in Java?

import java.util.*;

class AbstractMapDemo {
    public static void main(String[] args)
    {
  
        // Creating an AbstractMap
        AbstractMap<Integer, String>
            abstractMap = new HashMap<Integer, String>();

        // Mapping string values to int keys
        abstractMap.put(21, "Shot");
        abstractMap.put(42, "Java");
        abstractMap.put(34, "Yaaaayy");
    
        // Printing the AbstractMap
        System.out.println("The Mappings are: "
                           + abstractMap);
  
        // Clearing the AbstractMap using clear() method
        abstractMap.clear();

        // Printing the final AbstractMap
        System.out.println("The Final Mappings are: "
                           + abstractMap);
  
        
    }
}