code: public static float optFloat(@Nullable Bundle bundle, @Nullable String key) {
          return optFloat(bundle, key, 0.f);
      }
docs: Returns a optional float value. In other words, returns the value mapped by key if it exists and is a float.
  The bundle argument is allowed to be {@code null}. If the bundle is null, this method returns 0.0.
  @param bundle a bundle. If the bundle is null, this method will return 0.0.
  @param key a key for the value.
  @return a float value if exists, 0.0 otherwise.
  @see android.os.Bundle#getFloat(String)