Even when not using tracing, opencensus 0.18 types are required per this line in HttpRequest
/** OpenCensus tracing component. */
private final Tracer tracer = OpenCensusUtils.getTracer();
grpc code is more defensive to not require loading classes until used.
Even when not using tracing, opencensus 0.18 types are required per this line in
HttpRequestgrpc code is more defensive to not require loading classes until used.