DaggerActivityComponentBuilder.java

public static final class Builder {
  /**Other code**/
  public ActivityComponent build() {
    if (activityModule == null) {
      throw new IllegalStateException(ActivityModule.class.getCanonicalName() + " must be set");
    }
    if (appComponent == null) {
      throw new IllegalStateException(AppComponent.class.getCanonicalName() + " must be set");
    }
    return new DaggerActivityComponent(this);
  }
  
  public Builder activityModule(ActivityModule activityModule) {
    this.activityModule = Preconditions.checkNotNull(activityModule);
    return this;
  }

  public Builder appComponent(AppComponent appComponent) {
    this.appComponent = Preconditions.checkNotNull(appComponent);
    return this;
  }
}