...
    with open(src) as f:
        data = json.load(f)

    if subset_key:
        if subset_key in data:
            data = {subset_key: data[subset_key]}
        else:
            raise KeyError(f"The specified subset key '{subset_key}' does not exist in the JSON data.")
...

...
    for i, inner_dict in enumerate(data.values()):
        values_list = list(inner_dict.values())
        x_values = values_list[0]
        y_values = values_list[1]
...

...
    keys = list(data.keys())
    values = list(data.values())
...

visualize_plot(src: str, colors: list, linestyle: str = 'solid', linewidth: int = 1, title: str = 'Graph', x_axis: str = 'x-axis', y_axis: str = 'y-axis', subset_key: str = None)

visualize_pie(src: str, colors: list, title: str = 'Pie', subset_key: str = None)

visualize_bar(src: str, colors: list, title: str = 'Bars', x_axis: str = 'x-axis', y_axis: str = 'y-axis', subset_key: str = None)