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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 visualize_poisson_w(w, labels, filename, method='pca', figsize=(18,10), title='', **scatter_options):
 """ Saves a scatter plot of a visualization of W, the result from Poisson SE. """

    if method == 'pca':
        pca = PCA(2)
        r_dim_red = pca.fit_transform(w.T).T
    elif method == 'tsne':
        pass
    else:
        print("Method is not available. use 'pca' (default) or 'tsne'.")
        return
    visualize_dim_red(r_dim_red, labels, filename, figsize, title, **scatter_options)