code: public static boolean optBoolean(@Nullable Bundle bundle, @Nullable String key) {
          return optBoolean(bundle, key, false);
      }
docs: Returns a optional boolean value. In other words, returns the value mapped by key if it exists and is a boolean.
  The bundle argument is allowed to be {@code null}. If the bundle is null, this method returns false.
  @param bundle a bundle. If the bundle is null, this method will return false.
  @param key a key for the value.
  @return a boolean value if exists, false otherwise.
  @see android.os.Bundle#getBoolean(String)