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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 Flush(self):
 """Flushing actually applies all the operations in the pool."""

    DB.DeleteSubjects(self.delete_subject_requests, sync=False)

    for req in self.delete_attributes_requests:
      subject, attributes, start, end = req
      DB.DeleteAttributes(subject, attributes, start=start, end=end, sync=False)

    for req in self.set_requests:
      subject, values, timestamp, replace, to_delete = req
      DB.MultiSet(
          subject,
          values,
          timestamp=timestamp,
          replace=replace,
          to_delete=to_delete,
          sync=False)

    if (self.delete_subject_requests or self.delete_attributes_requests or
        self.set_requests):
      DB.Flush()

    for queue, notifications in self.new_notifications:
      DB.CreateNotifications(queue, notifications)
    self.new_notifications = []

    self.delete_subject_requests = []
    self.set_requests = []
    self.delete_attributes_requests = []