First error to occur in a
DeferredList if fireOnOneErrback is set.
FirstError and other
FirstError instances is defined as the comparison of the index and sub-failure of each instance.
FirstError instances don't compare equal to anything that isn't a ...
|The repr of
FirstError instances includes the repr of the wrapped failure's exception and the index of the
|The str of
FirstError instances includes the str of the entire wrapped failure (including its traceback and exception) and the index of the
|The index of the
Deferred in the
DeferredList where it happened.
Failure that occurred.