How does this compare to the Google Identity toolkit (<a href="https:&#x2F;&#x2F;developers.google.com&#x2F;identity&#x2F;toolkit&#x2F;?hl=en" rel="nofollow">https:&#x2F;&#x2F;developers.google.com&#x2F;identity&#x2F;toolkit&#x2F;?hl=en</a>) ?