How can I mock context using Mockito and Robolectric?

This is a snippet of my activity:

public class Search extends Activity
{
    private String TAG = "SEARCH";

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.search);
        Log.d(TAG, "About to call initialastion");
   //        new InitialisationTask(this).execute();
    }
}

In the line above, I can happily create and run unit tests as follows:

@RunWith(RobolectricTestRunner.class)
public class SearchTest {
    private Search searchActivity;
    private Button searchButton;
    private Button clearButton;
    private Button loginButton;
    private Button registerButton;
    private EditText searchEditText;

    @Before
    public void setUp() throws Exception {
        searchActivity = new Search();
        searchActivity.onCreate(null);

        searchButton = (Button) searchActivity.findViewById(R.id.btnPlateSearch);
        clearButton = (Button) searchActivity.findViewById(R.id.btnClearSearch);
        loginButton = (Button) searchActivity.findViewById(R.id.btnLogin);
        registerButton = (Button) searchActivity.findViewById(R.id.btnRegister);
        searchEditText = (EditText) searchActivity.findViewById(R.id.editTextInputPlate);
    }


    @Test
    public void assertSearchButtonHasCorrectLabel()
    {
        assertThat((String) searchButton.getText(), equalTo("Search"));
    }
}

However, if I uncomment the line new InitialisationTask(this).execute();in my activity, my tests fail, most likely due to a link to this.

What is the best approach for bullying in context?

I tried adding contextMock = mock(Context.class);to mine setUp(), but I'm not sure how I can set this layout to "searchActivity

thank