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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 get_leaf_children(gos_user, go2obj_arg):
 """Find all the GO descendants under all user GO IDs. Return leaf-level GO IDs."""

    childgoid2obj = {}
    for goid_usr in gos_user:
        goobj_usr = go2obj_arg[goid_usr]
        fill_childgoid2obj(childgoid2obj, goobj_usr)
    return set(go for go, o in childgoid2obj.items() if not o.children)