How can my smart contract or application access USD/HBAR exchange rate info from a file on the Hedera network (Hedera File Service)? The file I’m interested in is 0.0.112. I tried doing a query with the SDK from my application and it seems to get me the info, but how can I use this in… Read More How to get an exchange rate between USD and HBAR for use in Hedera application or smart contract?