def prefit(test, processor):
    alldf = reset(vcat(processor['impute'][1],test), drop = True)
    df =  complete(alldf, method = processor['impute'][0], ids = True, mice = processor['impute'][2])

    test = df[len(processor['impute'][1]):]
    if processor['dummies'] == -2:  test = dummies(test, dummies = True, ids = True)
    a = set(processor['columns'])
    b = set(columns(test))
    matching = set.intersection(a,b)
    not_matching = a.symmetric_difference(matching)
    test = test[list(matching)]