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