isSuccessful property
bool
get
isSuccessful
true if the status code is >= 200 && < 300 and nothing set an error.
The error clause matters when an interceptor throws while resolving an otherwise-2xx response: the body was never produced, so reporting success would hand the caller a null body.
Implementation
bool get isSuccessful =>
statusCode >= 200 && statusCode < 300 && error == null;