OptionalcanWhether the source can be written back to (a silent re-save).
OptionalencryptionThe encryption envelope the source is wrapped in, or null for plaintext.
OptionalformatThe resolved format key (e.g. 'xlsx') — the handle's resource type. If omitted, it is
derived from the path extension.
OptionallastWhen the source was last modified, in milliseconds since the epoch (stat-style), if known.
OptionalnameExplicit display name (without extension). If omitted, the name is derived from the path.
OptionalsizeThe last-known size of the source in bytes (stat-style), if known.
Options for constructing a WorkbookOrigin.