def exportValue(self, vf, value):
        m = StrStrHashMap(value)
        keysAndValues = []
        for i in m.keys():
            keysAndValues.append(i)
            keysAndValues.append(m[i])
def allowed_file(filename):
    return '.' in filename and \
           filename.rsplit('.', 1)[1] in app.config.get('ALLOWED_EXTENSIONS')