@Override public A getValue() {
    //noinspection ConstantConditions
    return valueCallback.getValueInternal(0f, 0f, valueCallbackValue, valueCallbackValue, getProgress(), getProgress(), getProgress());
  }
If this doesn't return 1, then {@link #setProgress(float)} will always clamp the progress
to 0.
lottie/src/main/java/com/airbnb/lottie/animation/keyframe/ValueCallbackKeyframeAnimation.java