OptionalfileName: stringOptionalcontent: string | BlobOptionalextension: stringOptionalcontentType: stringName the browser saves the file under, without the extension, which is added
What the file holds: text, which is wrapped in a Blob of contentType, or a Blob saved
as it is
Extension added to the file name after a dot, such as txt, csv or json
MIME type declared for text content, such as text/plain or application/json
Feeds
asset.download: what to write into the downloaded file, what to call it and which content type to declare.