code: public Quaternionf invert(Quaternionf dest) {
          float invNorm = 1.0f / (x * x + y * y + z * z + w * w);
          dest.x = -x * invNorm;
          dest.y = -y * invNorm;
          dest.z = -z * invNorm;
          dest.w = w * invNorm;
          return dest;
      }
docs: /* (non-Javadoc)
  @see org.joml.Quaternionfc#invert(org.joml.Quaternionf)