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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 mark_as_required(self):
 """Adds this loss to the MARKED_LOSSES collection."""

    if self not in tf.get_collection(bookkeeper.GraphKeys.MARKED_LOSSES):
      tf.add_to_collection(bookkeeper.GraphKeys.MARKED_LOSSES, self)