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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 subtree_leaf_positions(subtree):
 """Return tree positions of all leaves of a subtree."""

    relative_leaf_positions = subtree.treepositions('leaves')
    subtree_root_pos = subtree.treeposition()
    absolute_leaf_positions = []
    for rel_leaf_pos in relative_leaf_positions:
        absolute_leaf_positions.append( subtree_root_pos + rel_leaf_pos)
    return absolute_leaf_positions