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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 transformer(grid):
 """ Choose transformer and add to grid's station Parameters grid: LVGridDing0 LV grid data """


    # choose size and amount of transformers
    transformer, transformer_cnt = select_transformers(grid)

    # create transformers and add them to station of LVGD
    for t in range(0, transformer_cnt):
        lv_transformer = TransformerDing0(
            grid=grid,
            id_db=id,
            v_level=0.4,
            s_max_longterm=transformer['S_nom'],
            r=transformer['R'],
            x=transformer['X'])

        # add each transformer to its station
        grid._station.add_transformer(lv_transformer)