MetricKit iOS 14.5 to 15.0 API Differences

MXMetricManager.h

Modified -[MXMetricManagerSubscriber didReceiveMetricPayloads:]

	Optional
From	Required
To	Optional

MXSignpost.h

Added #def MXSignpostAnimationIntervalBegin

MXSignpostMetric.h

Added MXSignpostIntervalData.cumulativeHitchTimeRatio