toString() from DefaultIterableDiffer is only used in tests and should not
be part of the production code. toString() methods from differs add
~ 0.3KB (min+gzip) to the production bundle size.
toString() from DefaultKeyValueDiffer is only used in tests and should not
be part of the production code. toString() methods from differs add
~ 0.3KB (min+gzip) to the production bundle size.