What is the REST API for reserving a Public IP(not VIP)

Hi,

We are trying to reserve a public IP for our VM with REST API. https://msdn.microsoft.com/en-us/library/dn690118.aspx mentioned there is REST API support, but we can't find anywhere that defines the actual REST API for setting the Public IP. Could you send us either the link or API detail info? 

And another question is that is there a Elastic IP available so that the VM Public IP can survived the power reboot?

Thanks.

Li