TabLayout with icons only instead of text

Question

I don't know how to use only icons instead of texts in tabs in my TabsAccessorAdapter Activity. Some one can help me adapting the existing code. I tried finding out but didn't get any success.

I also do not know if this is the best way to create and display a TabLayout I hope you can help me.

My code:

import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;

public class TabsAccessorAdapter extends FragmentStatePagerAdapter {
    public TabsAccessorAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int i)
    {
        switch (i)
        {
            case 0:
                ChatsFragment chatsFragment = new ChatsFragment();
                return chatsFragment;

            case 1:
                ContactsFragment contactsFragment = new ContactsFragment();
                return contactsFragment;

            case 2:
                RequestsFragment requestsFragment = new RequestsFragment();
                return requestsFragment;

            default:
                return null;
        }
    }

    @Override
    public int getCount() {
        return 3;
    }

    @Nullable
    @Override
    public CharSequence getPageTitle(int position)
    {
        switch (position)
        {
            case 0:
                return "Conversas";

            case 1:
                return "Contactos";

            case 2:
                return "Pedidos";

            default:
                return null;
        }
    }
}