/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package graphalgorithms;

/**
 *
 * @author piyush
 */
public class Forest {
    private Tree [] trees;
    
    Forest(Tree []trees){
        this.trees=trees;
    }
    
}

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package graphalgorithms;
import java.util.ArrayList;
import java.util.List;

/**
 *
 * @author piyush
 */
public class Forest {
    private List <Tree> trees= new ArrayList<>();
    
    Forest(ArrayList <Tree> trees){
        this.trees=trees;
        
    }
    
    
    
    
}

Update Forest.java