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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get(self, value):
 """ Get an enumeration item for an enumeration value. :param unicode value: Enumeration value. :raise InvalidEnumItem: If ``value`` does not match any known enumeration value. :rtype: EnumItem """

        _nothing = object()
        item = self._values.get(value, _nothing)
        if item is _nothing:
            raise InvalidEnumItem(value)
        return item