encodeTimeout static method
gRPC timeout grammar (grpc-timeout metadata):
Implementation
static String encodeTimeout(Duration timeout) {
var ms = timeout.inMilliseconds;
if (timeout - Duration(milliseconds: ms) > Duration.zero) ms++;
if (ms <= 99999999) return '${ms}m';
var secs = timeout.inSeconds;
if (timeout - Duration(seconds: secs) > Duration.zero) secs++;
return '${secs}S';
}