Optional
alwaysAlways applicable
Optional
ifAt least one waitable has a defined error
Optional
ifAt least one waitable doesn't have a defined value or at least one waitable has a defined error
Optional
ifAll waitables have defined values
Optional
ifAt least one waitable doesn't have a defined value but no waitables have defined errors
Transformers that are used depending on the state of the waitables.
The first applicable transformer is used, evaluated in the following order:
ifLoaded
,ifError
,ifLoading
,ifErrorOrLoading
,always