From 3f0173c15f9faddc338dbc33a9bf8275d344befa Mon Sep 17 00:00:00 2001
From: TianlinZhao <tianlinzhao@google.com>
Date: Thu, 30 Jul 2020 19:28:03 -0400
Subject: [PATCH] tracer

---
 .../opentelemetry/trace/default_span.h        | 30 ++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/api/include/opentelemetry/trace/default_span.h b/api/include/opentelemetry/trace/default_span.h
index 249a4956ef..1c6ab99738 100644
--- a/api/include/opentelemetry/trace/default_span.h
+++ b/api/include/opentelemetry/trace/default_span.h
@@ -7,8 +7,36 @@
 
 #define pass
 OPENTELEMETRY_BEGIN_NAMESPACE
-class DefaultTracer;
 namespace trace {
+class DefaultTracer: public Tracer {
+public:
+  ~DefaultTracer() = default;
+
+  /**
+   * Starts a span.
+   *
+   * Optionally sets attributes at Span creation from the given key/value pairs.
+   *
+   * Attributes will be processed in order, previous attributes with the same
+   * key will be overwritten.
+   */
+  nostd::unique_ptr<Span> StartSpan(nostd::string_view name,
+                                    const KeyValueIterable &attributes,
+                                    const StartSpanOptions &options = {}) noexcept
+  {
+     return DefaultSpan::GetInvalid();
+  }
+
+  void ForceFlushWithMicroseconds(uint64_t timeout) noexcept
+  {
+    pass;
+  }
+
+  void CloseWithMicroseconds(uint64_t timeout) noexcept
+  {
+    pass;
+  }
+};
 class DefaultSpan: public Span {
   public:
     // Returns an invalid span.