### Question:
ViewGroupCompat { public static void setTransitionGroup(@NonNull ViewGroup group, boolean isTransitionGroup) { if (Build.VERSION.SDK_INT >= 21) { group.setTransitionGroup(isTransitionGroup); } else { group.setTag(R.id.tag_transition_group, isTransitionGroup); } } private  ViewGroupCompat(); @Deprecated static boolean onRequestSendAccessibilityEvent(ViewGroup group, View child,
            AccessibilityEvent event); @Deprecated static void setMotionEventSplittingEnabled(ViewGroup group, boolean split); static int getLayoutMode(@NonNull ViewGroup group); static void setLayoutMode(@NonNull ViewGroup group, int mode); static void setTransitionGroup(@NonNull ViewGroup group, boolean isTransitionGroup); static boolean isTransitionGroup(@NonNull ViewGroup group); @ScrollAxis @SuppressWarnings("RedundantCast") // Intentionally invoking interface method. static int getNestedScrollAxes(@NonNull ViewGroup group); static final int LAYOUT_MODE_CLIP_BOUNDS; static final int LAYOUT_MODE_OPTICAL_BOUNDS; }### Answer:
@Test public void setTransitionGroup() { assertFalse(ViewGroupCompat.isTransitionGroup(mViewGroup)); InstrumentationRegistry.getInstrumentation().runOnMainSync(new Runnable() { @Override public void run() { ViewGroupCompat.setTransitionGroup(mViewGroup, true); } }); assertTrue(ViewGroupCompat.isTransitionGroup(mViewGroup)); InstrumentationRegistry.getInstrumentation().runOnMainSync(new Runnable() { @Override public void run() { ViewGroupCompat.setTransitionGroup(mViewGroup, false); } }); assertFalse(ViewGroupCompat.isTransitionGroup(mViewGroup)); }