Random groups for a tournament

Tournament.java

import java.util.ArrayList;
import java.util.Random;

class Team {
    private String name;

    public Team(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }


    @Override
    public String toString() {
        return "{ Team " + name + " }";
    }
}

class Pool {

    private ArrayList<Team> teams = new ArrayList<>();
    private ArrayList<ArrayList<Team>> schema;

    private int numberOfGroups = 0, teamsGroup = 0;

    public Pool(int numberOfGroups, int teamsGroup) {
        this.numberOfGroups = numberOfGroups;
        this.teamsGroup = teamsGroup;
        schema = new ArrayList<>();
        for (int i = 0; i < numberOfGroups; i++) {
            ArrayList<Team> group = new ArrayList<>();
            schema.add(group);
        }
    }

    public void scheduleTeams() {
        ArrayList<Team> copy = new ArrayList<>();
        copy.addAll(teams);

        Random random = new Random();

        while (!copy.isEmpty()) {
            int t = random.nextInt(copy.size());
            Team team = copy.get(t);
            
            int g = random.nextInt(numberOfGroups);
            ArrayList<Team> group = schema.get(g);

            if (group.size() < teamsGroup) {
                group.add(team);
                copy.remove(t);
            }
        }

        System.out.println(schema);
    }


    public void createTeams() {
        teams.add(new Team("Team 1"));
        teams.add(new Team("Team 2"));
        teams.add(new Team("Team 3"));
        teams.add(new Team("Team 4"));
        teams.add(new Team("Team 5"));
        teams.add(new Team("Team 6"));
        teams.add(new Team("Team 7"));
        teams.add(new Team("Team 8"));
        teams.add(new Team("Team 9"));
        teams.add(new Team("Team 10"));
        teams.add(new Team("Team 11"));
        teams.add(new Team("Team 12"));
    }
}

public class Main {
    public static void main(String[] args) {
        Pool p = new Pool(4, 3);
        p.createTeams();
        p.scheduleTeams();
    }
}