utils/src/main/java/org/robolectric/util/inject/Injector.java
@Nonnull private <T> T getInstance(@Nonnull Key<T> key) {
    try {
      return getInstanceInternal(key);
    } catch (UnsatisfiedDependencyException e) {
      throw e.asInjectionException(key);
    }
  }
@Nonnull private <T> T getInstance(@Nonnull Key<T> key) {
    try {
      return getInstanceInternal(key);
    } catch (UnsatisfiedDependencyException e) {
      throw e.asInjectionException(key);
    }
  }
Finds an instance for the given key. Calls are guaranteed idempotent.