Dagger @Provides methods may not return null unless annotated with
@Nullable. Such a method will cause a NullPointerException at runtime if the
return null path is ever taken.
If you believe the return null path can never be taken, please throw a
RuntimeException instead. Otherwise, please annotate the method with
@Nullable.
Suppress false positives by adding the suppression annotation @SuppressWarnings("DaggerProvidesNull") to the enclosing element.