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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 is_empty(self):
 """Returns True if all child date elements present are empty and other nodes are not set. Returns False if any child date elements are not empty or other nodes are set."""

        return all(date.is_empty() for date in [self.created, self.issued]) \
               and not self.publisher