function getRawContent(blob) {
    if (hasRawContent(blob)) {
        return blob[rawContent]();
    }
    else {
        return blob;
    }
}
Create an object that implements the File interface. This object is intended to be
passed into RequestBodyType.formData, and is not guaranteed to work as expected in
other situations.

Use this function to:
- Create a File object for use in RequestBodyType.formData in environments where the
  global File object is unavailable.
- Create a File-like object from a readable stream without reading the stream into memory.

@param stream - the content of the file as a callback returning a stream. When a File object made using createFile is
                 passed in a request's form data map, the stream will not be read into memory
                 and instead will be streamed when the request is made. In the event of a retry, the
                 stream needs to be read again, so this callback SHOULD return a fresh stream if possible.
@param name - the name of the file.
@param options - optional metadata about the file, e.g. file name, file size, MIME type.