def inverted(self):
        '''
        Return a version of this instance with inputs replaced by outputs and vice versa.
        '''
        return Instance(input=self.output, output=self.input,
                        annotated_input=self.annotated_output,
                        annotated_output=self.annotated_input,
                        alt_inputs=self.alt_outputs,
                        alt_outputs=self.alt_inputs,
                        source=self.source)
Return a version of this instance with inputs replaced by outputs and vice versa.