def need(self, folder, page=None, perpage=None):
assert isinstance(page, int) or page is None<EOL>assert isinstance(perpage, int) or perpage is None<EOL>return self.get('<STR_LIT>', params={'<STR_LIT>': folder,<EOL>'<STR_LIT>': page,<EOL>'<STR_LIT>': perpage})<EOL>
Returns lists of files which are needed by this device in order
        for it to become in sync.

            Args:
                folder (str):
                page (int): If defined applies pagination accross the
                    collection of results.
                perpage (int): If defined applies pagination across the
                    collection of results.

            Returns:
                dict