What unwrap throws for a failure envelope. message is the envelope's error; code and details are copied from it, so a catch block can branch on the code as it would on the envelope.
message
error
code
details
catch
Readonly
The failure's code, such as LOCKED or NOT_SUPPORTED.
LOCKED
NOT_SUPPORTED
Optional
The failure's details, when it has any.
What unwrap throws for a failure envelope.
messageis the envelope'serror;codeanddetailsare copied from it, so acatchblock can branch on the code as it would on the envelope.