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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 _iris_cell_methods_to_str(cell_methods_obj):
 """ Converts a Iris cell methods into a string """

    cell_methods = []
    for cell_method in cell_methods_obj:
        names = ''.join(['{}: '.format(n) for n in cell_method.coord_names])
        intervals = ' '.join(['interval: {}'.format(interval)
                              for interval in cell_method.intervals])
        comments = ' '.join(['comment: {}'.format(comment)
                             for comment in cell_method.comments])
        extra = ' '.join([intervals, comments]).strip()
        if extra:
            extra = ' ({})'.format(extra)
        cell_methods.append(names + cell_method.method + extra)
    return ' '.join(cell_methods)