Get file thumbnail

Retrieves a thumbnail, or smaller image representation, of a file. Sizes of `32x32`,`64x64`, `128x128`, and `256x256` can be returned in the `.png` format and sizes of `32x32`, `160x160`, and `320x320` can be returned in the `.jpg` format. Thumbnails can be generated for the image and video file formats listed [found on our community site][1]. [1]: https://community.box.com/t5/Migrating-and-Previewing-Content/File-Types-and-Fonts-Supported-in-Box-Content-Preview/ta-p/327