@staticmethod
def _fix_encoding(var):
    """ Strip input string from non unicode symbols

            Parameters
            ----------
            var: str
                input string which can contain non unicode symbols

            Returns
            -------
                str, only unicode symbols

            Examples
            --------
                >>> Opendap._fix_encoding(u'åsnes')
                'snes
                >>> Opendap._fix_encoding('asnes')
                'asnes'
        """
    return str(var.encode('ascii', 'ignore').decode())
