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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 extension_sort_key(extension):
 """Returns the sorting key for an extension. The sorting key can be used to sort a list of extensions into the order that is used in the Khronos C OpenGL headers. :param Extension extension: Extension to produce sort key for :returns: A sorting key """

    name = extension.name
    category = name.split('_', 2)[1]
    return (0, name) if category in ('ARB', 'KHR', 'OES') else (1, name)