Method preWrite

test/cpp/src/TestServer.cpp:392–392

    communicate("postRead", ctx, fn_name);
  }
  void preWrite(void* ctx, const char* fn_name) override { communicate("preWrite", ctx, fn_name); }
  void postWrite(void* ctx, const char* fn_name, uint32_t bytes) override {
    (void)bytes;
    communicate("postWrite", ctx, fn_name);