':param ident: user identifier
:param name_id: NameID instance'

def store(self, ident, name_id):

    if isinstance(ident, unicode):
        ident = ident.encode('utf-8')
    try:
        val = self.db[ident].split('    ')
    except KeyError:
        val = []
    _cn = code(name_id)
    val.append(_cn)
    self.db[ident] = '    '.join(val)
    self.db[name_id.text] = ident
