type mismatchFailure … type HaveExactElementsMatcher … func (matcher *HaveExactElementsMatcher) Match(actual interface{ … } func (matcher *HaveExactElementsMatcher) FailureMessage(actual interface{ … } func (matcher *HaveExactElementsMatcher) NegatedFailureMessage(actual interface{ … } func (matcher *HaveExactElementsMatcher) resetState() { … }