The Testing Pyramid, shown in the Figure, illustrates how your app should include the three categories of tests: small, medium, and large. Small tests are unit tests that :

Each time your test invokes onView(), Espresso waits to perform the corresponding UI action or assertion until the following synchronization conditions are met: (Choose three.)

RecyclerView is a subclass of ViewGroup and is a more resource-efficient way to display scrollable lists. Instead of creating a View for each item that may or may not be visible on the screen, RecyclerView:

Assume that an app includes a default set of graphics and two other sets of graphics, each optimized for a different device setup:
res/drawable/
Contains default graphics. res/drawable-small-land-stylus/
Contains graphics optimized for use with a device that expects input from a stylus and has a QVGA low- density screen in landscape orientation. res/drawable-ja/ Contains graphics optimized for use with Japanese.
What happens if the app runs on a device that is configured to use Japanese and, at the same time, the device happens to be one that expects input from a stylus and has a QVGA low-density screen in landscape orientation?

When your code execution reaches the breakpoint, Android Studio pauses execution of your app. You can then use the tools in the Debugger tab to identify the state of the app. With Step Over you can