In order to reduce the number of external dependencies on the application being tested,
Robolectric's shadows are split into various add-on packages. Only shadows for classes provided in
the base Android SDK are provided by the main Robolectric module. Additional shadows are provided in
dedicated packages.
Note
Robolectric 3.4 doesn't include the shadows- prefix in the package
name (i.e., org.robolectric:playservices and org.robolectric:httpclient).
Before Robolectric 3.4, org.robolectric:playservices was named shadow-play-services.