struct LogInfoRawStream : public llvm::raw_ostream {
  LogInfoRawStream() { SetUnbuffered(); }
  ~LogInfoRawStream() override = default;
  uint64_t current_pos() const override { return 0; }

  void write_impl(const char* ptr, size_t size) override {
    fprintf(stderr, "%.*s", static_cast<int>(size), ptr);
  }
};

// Simple raw_ostream that prints to a file.
struct WritableFileRawStream : public llvm::raw_ostream {

  explicit WritableFileRawStream(WritableFile* file) : file(file) {
    SetUnbuffered();
  }
  ~WritableFileRawStream() override = default;
  uint64_t current_pos() const override { return 0; }

  void write_impl(const char* ptr, size_t size) override {
    // If an error is encountered, null out the file.
    if (file) {
      Status s = file->Append(StringPiece(ptr, size));
      if (!s.ok()) {

struct StringStream : public llvm::raw_ostream {
  StringStream() { SetUnbuffered(); }
  ~StringStream() override = default;
  uint64_t current_pos() const override { return 0; }

  void write_impl(const char* ptr, size_t size) override {
    ss.write(ptr, size);
  }
  std::stringstream ss;
};

class TestPassInstrumentation : public ::testing::Test {
 public:

  }

  uint64_t current_pos() const override {
    int64_t position;
    if (file_->Tell(&position).ok()) {
      return position;
    } else {
      return -1;
    }
  }

  void write_impl(const char* ptr, size_t size) override {
    if (file_ && !file_->Append(tsl::StringPiece(ptr, size)).ok()) {
      file_ = nullptr;
    }
  }

  std::unique_ptr<tsl::WritableFile> file_;
};

      // a subroutine or not, so it's important we have a working current_pos().
      LOG(WARNING)
          << "Couldn't query file position. Stream might be malformed.\n";
      return -1;
    }
  }

  void write_impl(const char* ptr, size_t size) override {
    // Write the file if it is still valid. If the write fails, null out the
    // file to avoid encountering another error.

}

type writerImpl struct {
	workDir string
}

// NewFileWriter creates a new FileWriter that stores files under workDir.
func NewFileWriter(workDir string) FileWriter {
	return &writerImpl{
		workDir: workDir,
	}
}

// WriteYAML writes the given YAML content to one or more YAML files.
func (w *writerImpl) WriteYAML(filenamePrefix string, contents ...string) ([]string, error) {