def METHOD_NAME(url, cls, callback):
    request = window.XMLHttpRequest.new()
    request.open("GET", url, True)
    request.responseType = "arraybuffer"
    def f(buffer):
        cls.buffer = buffer
        callback()
    @bind(request, 'load')
    def load(ev):
        Config.context.decodeAudioData(request.response, f)
    request.send()