def __repr__(self):
        try:
            equiv = dict(self)
        except __HOLE__:
            # Some keys are unhashable, fall back on .items()
            equiv = list(self.items())
        return '%s(%r, %s)' % (self.__class__.__name__,
                               self._transform, repr(equiv))
dataset/ETHPy150Open fluentpython/example-code/03-dict-set/transformdict.py/TransformDict.__repr__