A string representation of this object.
Some classes have a default textual representation,
often paired with a static
parse function (like int.parse).
These classes will provide the textual representation as
their string representation.
Other classes have no meaningful textual representation
that a program will care about.
Such classes will typically override
toString to provide
useful information when inspecting the object,
mainly for debugging or logging.
@override String toString() => ''' MissingDummyValueError: $type This means Mockito was not smart enough to generate a dummy value of type '$type'. Please consider using either 'provideDummy' or 'provideDummyBuilder' functions to give Mockito a proper dummy value. Please note that due to implementation details Mockito sometimes needs users to provide dummy values for some types, even if they plan to explicitly stub all the called methods. ''';