code: public static Crouton makeText(Activity activity, CharSequence text, Style style, int viewGroupResId) {
      return new Crouton(activity, text, style, (ViewGroup) activity.findViewById(viewGroupResId));
    }
docs: Creates a {@link Crouton} with provided text and style for a given
  activity.
  
  @param activity
  The {@link Activity} that represents the context in which the Crouton should exist.
  @param text
  The text you want to display.
  @param style
  The style that this {@link Crouton} should be created with.
  @param viewGroupResId
  The resource id of the {@link ViewGroup} that this {@link Crouton} should be added to.
  
  @return The created {@link Crouton}.