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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 setPath(self, folderpath, specfiles=None):
 """Changes the folderpath of the specified specfiles. The folderpath is used for saving and loading of ``mrc`` files. :param specfiles: the name of an ms-run file or a list of names. If None all specfiles are selected. :type specfiles: None, str, [str, str] :param folderpath: a filedirectory """

        if specfiles is None:
            specfiles = [_ for _ in viewkeys(self.info)]
        else:
            specfiles = aux.toList(specfiles)

        _containerSetPath(self, folderpath, specfiles)