shadows/framework/src/main/java/org/robolectric/shadows/ShadowToast.java
public static void reset() {
    ShadowApplication shadowApplication = Shadow.extract(RuntimeEnvironment.application);
    shadowApplication.getShownToasts().clear();
  }
public static void reset() {
    ShadowApplication shadowApplication = Shadow.extract(RuntimeEnvironment.application);
    shadowApplication.getShownToasts().clear();
  }
Discards the recorded {@code Toast}s. Shown toasts are automatically cleared between
tests. This method allows the user to discard recorded toasts during the test in order to make assertions clearer
e.g:

<pre>

// Show a single toast
myClass.showToast();

assertThat(ShadowToast.shownToastCount()).isEqualTo(1);
ShadowToast.reset();

// Show another toast
myClass.showToast();

assertThat(ShadowToast.shownToastCount()).isEqualTo(1);

</pre>