GetAttachment returns an attachment by name.
The attachment id.
OK
The name of the attachment. Format: attachments/{attachment}
Output only. The creation timestamp.
The filename of the attachment.
Input only. The content of the attachment.
Optional. The external link of the attachment.
The MIME type of the attachment.
Output only. The size of the attachment in bytes.
Optional. The related memo. Refer to Memo.name. Format: memos/{memo}