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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 expand(self, filetype, **kwargs):
        ''' Expand a wildcard path locally

        Parameters
        ----------
        filetype : str
            File type parameter.

        as_url: bool
            Boolean to return SAS urls

        refine: str
            Regular expression string to filter the list of files by
            before random selection

        Returns
        -------
        expand : list
            List of expanded full paths of the given type.

        '''

        full = kwargs.get('full', None)
        if not full:
            full = self.full(filetype, **kwargs)

        # assert '*' in full, 'Wildcard must be present in full path'
        files = glob(full)

        # return as urls?
        as_url = kwargs.get('as_url', None)
        newfiles = [self.url('', full=full) for full in files] if as_url else files

        # optionally refine the results
        refine = kwargs.get('refine', None)
        if refine:
            newfiles = self.refine(newfiles, refine, **kwargs)

        return newfiles