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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 _create_marks(fig, marks=[bq.Mark], options={}, params={}):
 """ Initializes and returns marks for a figure as a list. Each mark is passed in as a class. The plot options should be passed into options. Any additional parameters to initialize plot components are passed into For example, when initializing two marks you can assign different colors to each one: params={ 'marks': [ {'colors': [DARK_BLUE]}, {'colors': [GOLDENROD]}, ] } If the param value is a function, it will be called with the options dict augmented with all previously created plot elements. This permits dependencies on plot elements: params={ 'marks': {'scale': lambda opts: opts['x_sc'] } } """

    params = _merge_with_defaults(params)

    # Although fig provides scale_x and scale_y properties, the scales on the
    # axes are the only ones that are actually used.
    x_ax, y_ax = fig.axes
    x_sc, y_sc = x_ax.scale, y_ax.scale

    options = tz.merge(options, {'x_sc': x_sc, 'y_sc': y_sc})

    marks = [
        mark_cls(**_call_params(mark_params, options))
        for mark_cls, mark_params in zip(marks, params['marks'])
    ]
    return marks