message: statsd: remove undefined method
  This method is declared in the header but has no implementation and is not called anywhere.
diff: @@ -102,7 +102,6 @@ private:
  ~TlsSink() override;
  void beginFlush(bool expect_empty_buffer);
  - void checkSize();
  void commonFlush(const std::string& name, uint64_t value, char stat_type);
  void flushCounter(const std::string& name, uint64_t delta);
  void flushGauge(const std::string& name, uint64_t value);
  