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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 finalise(output=None, figsize=None, tight=True, **kwargs):
 """ Finalise a plot. Display or show the plot, then close it. Arguments: output (str, optional):
 Path to save figure to. If not given, show plot. figsize ((float, float), optional):
 Figure size in inches. **kwargs: Any additional arguments to pass to plt.savefig(). Only required if output is not None. """

    import matplotlib.pyplot as plt

    # Set figure size.
    if figsize is not None:
        plt.gcf().set_size_inches(*figsize)

    # Set plot layout.
    if tight:
        plt.tight_layout()

    if output is None:
        plt.show()
    else:
        plt.savefig(output, **kwargs)
        io.info("Wrote", output)
    plt.close()