android - how to return fragment of compatible type -

i using viewpager fragments. defined 3 fragments, each in separate class file "frag_1, frag_2, frag_3" extends fragment class. when instantiate , object of fragment class shown below in switch-case receive incompatible type error , says:

 required xx.xx.xx.app.fragment  , found vpager_00.frag_1 

how solve it

code:

public class vpageradapter extends fragmentstatepageradapter {  private int mnumoftabs;  public vpageradapter(fragmentmanager fm, int numoftabs) {     super(fm);     this.mnumoftabs = numoftabs; }  @override public fragment getitem(int position) {     switch (position) {         case 0:             frag_1 tab1 = new frag_1();             return tab1;         case 1:             frag_2 tab2 = new frag_2();             return tab2;         case 2:             frag_3 tab3 = new frag_3();             return tab3;         default:             return null;     } } 

imports in vpageradapter class:

import android.support.v4.app.fragment; import android.support.v4.app.fragmentmanager; import android.support.v4.app.fragmentstatepageradapter; import com.example.com.vpager_00.frag_1; import com.example.com.vpager_00.frag_2; import com.example.com.vpager_00.frag_3;