Как переключать контент tabItem через SectionsPagerAdapter?

private SectionsPagerAdapter mSectionsPagerAdapter;

   
    private ViewPager mViewPager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_class1);

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
       
        mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

      
        mViewPager = (ViewPager) findViewById(R.id.container);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);

        mViewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
        tabLayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(mViewPager));


    }

public class SectionsPagerAdapter extends FragmentPagerAdapter {

        public SectionsPagerAdapter(FragmentManager fm) {
            super(fm);
        }

      @Override
       public Fragment getItem(int position) {
          Fragment fragment =null;
            switch (position) {
                case 0:

            }
            return null;
        }

        @Override
        public int getCount() {
            // Show 5 total pages.
            return 5;
        }
    }