Method MyBuffer

cpp/src/arrow/buffer_test.cc:135–139

class MyBuffer : public Buffer {
 public:
  MyBuffer(std::shared_ptr<MemoryManager> mm, const std::shared_ptr<Buffer>& parent)
      : Buffer(parent->data(), parent->size()) {
    parent_ = parent;
    SetMemoryManager(mm);
  }
};

std::shared_ptr<MemoryManager> MyDevice::default_memory_manager() {