type FUNC_OnRtcStats = Option<unsafe extern "C" fn(duration: c_uint, txBytes: c_uint, rxBytes: c_uint, txAudioBytes: c_uint, txVideoBytes: c_uint, rxAudioBytes: c_uint, rxVideoBytes: c_uint, txKBitRate: c_ushort, rxKBitRate: c_ushort, rxAudioKBitRate: c_ushort, txAudioKBitRate: c_ushort, rxVideoKBitRate: c_ushort, txVideoKBitRate: c_ushort, lastmileDelay: c_ushort, txPacketLossRate: c_ushort, rxPacketLossRate: c_ushort, userCount: c_uint, cpuAppUsage: f64, cpuTotalUsage: f64, gatewayRtt: c_int, memoryAppUsageRatio: f64, memoryTotalUsageRatio: f64, memoryAppUsageInKbytes: c_int)>;