基本的なサムネイルの取得

curl -i -X GET "https://api.box.com/2.0/files/12345/thumbnail.png" \
     -H "authorization: Bearer <ACCESS_TOKEN>"

await client.files.getFileThumbnailById(
  thumbnailFile.id,
  'png' as GetFileThumbnailByIdExtension,
);

client.files.get_file_thumbnail_by_id(
    thumbnail_file.id, GetFileThumbnailByIdExtension.PNG
)

await client.Files.GetFileThumbnailByIdAsync(fileId: thumbnailFile.Id, extension: GetFileThumbnailByIdExtension.Png);

try await client.files.getFileThumbnailById(fileId: thumbnailFile.id, extension_: GetFileThumbnailByIdExtension.png, downloadDestinationUrl: destinationPath)

client.getFiles().getFileThumbnailById(thumbnailFile.getId(), GetFileThumbnailByIdExtension.PNG)

file_id = '11111'

thumbnail = client.file(file_id).get_thumbnail_representation('92x92', extension='jpg')

Stream thumbnailContents = await client.FilesManager.GetThumbnailAsync("11111", maxWidth: 160, maxHeight: 160);