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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def emit(_):
 """Serialize metrics to the memory mapped buffer."""

    if not initialized:
        raise NotInitialized

    view = {
        'version': __version__,
        'counters': {},
        'gauges': {},
        'histograms': {},
        'meters': {},
        'timers': {},
    }

    for (ty, module, name), metric in six.iteritems(all_metrics):
        view[ty]['%s.%s' % (module, name)] = metric.view()

    marshalled_view = marshal.dumps(view)
    if len(marshalled_view) > MAX_MARSHALLED_VIEW_SIZE:
        log.warn(
            'Marshalled length too large, got %d, max %d. '
            'Try recording fewer metrics or increasing '
            'MAX_MARSHALLED_VIEW_SIZE'
            % (len(marshalled_view), MAX_MARSHALLED_VIEW_SIZE))
        return
    marshalled_metrics_mmap.seek(0)
    try:
        # Reading and writing to/from an mmap'ed buffer is not guaranteed
        # to be atomic, so we must serialize access to it.
        uwsgi.lock()
        marshalled_metrics_mmap.write(marshalled_view)
    finally:
        uwsgi.unlock()