private static List<String> defaultExamples(MethodDescriptor method) {
        try {
            final DynamicMessage defaultInput = DynamicMessage.getDefaultInstance(method.getInputType());
            final String serialized = defaultExamplePrinter.print(defaultInput).trim();
            if ("{\n}".equals(serialized) || "{}".equals(serialized)) {
                // Ignore an empty object.
                return ImmutableList.of();
            }
            return ImmutableList.of(serialized);
        } catch (InvalidProtocolBufferException e) {
            return ImmutableList.of();
        }
    }
{@link DocServicePlugin} implementation that supports {@link GrpcService}s.
grpc/src/main/java/com/linecorp/armeria/internal/server/grpc/GrpcDocServicePlugin.java