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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 _load_all_bookmarks():
 """Load all bookmarks from config."""

    slots = CONF.get('editor', 'bookmarks', {})
    for slot_num in list(slots.keys()):
        if not osp.isfile(slots[slot_num][0]):
            slots.pop(slot_num)
    return slots