Central Bank Rate Validation

Before returning data, the returned central bank data is validated with the following checks:

• The RateFeed checks that the returned central bank rate is at most as old as the _stalenessThreshold. Note: Even though central bank rates seldom change (on the order of a few times a year at most), oracles are still expected to update the rate to be newer than the _stalenessThreshold, even if they are updating to the same rates as served in the previous round. This staleness threshold is set by the MCAG_MANAGER_ROLE.

• Before data is accepted in a round, the MCAGAggregator checks that the rate feed's answer is less than a preconfigured maximum value, and that the newly transmitted rate has not changed too drastically from the previous rate. See the MCAGAggregator Volatility Check section for exact calculations on how this is done.