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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 busy(self):
 """Return if the connection is currently executing a query or is locked by a session that still exists. :rtype: bool """

        if self.handle.isexecuting():
            return True
        elif self.used_by is None:
            return False
        return not self.used_by() is None