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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 remove_prefix(cls, suffix):
 """"Remove the class prefix from the suffix The collection pass the full suffix used in the filters to the index. But to know if it is valid, we have to remove the prefix to get the real suffix, for example to check if the suffix is handled by the index. Parameters suffix: str The full suffix to split Returns ------- str or None The suffix without the prefix. None if the resting suffix is '' Raises ------ IndexError: If the suffix doesn't contain the prefix """


        if not cls.prefix:
            return suffix
        if cls.prefix == suffix:
            return None
        return (suffix or '').split(cls.prefix + '__')[1] or None