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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 start_rest_api(host, port, connection, timeout, registry, client_max_size=None):
 """Builds the web app, adds route handlers, and finally starts the app. """

    loop = asyncio.get_event_loop()
    connection.open()
    app = web.Application(loop=loop, client_max_size=client_max_size)
    app.on_cleanup.append(lambda app: connection.close())

    # Add routes to the web app
    LOGGER.info('Creating handlers for validator at %s', connection.url)

    handler = RouteHandler(loop, connection, timeout, registry)

    app.router.add_post('/batches', handler.submit_batches)
    app.router.add_get('/batch_statuses', handler.list_statuses)
    app.router.add_post('/batch_statuses', handler.list_statuses)

    app.router.add_get('/state', handler.list_state)
    app.router.add_get('/state/{address}', handler.fetch_state)

    app.router.add_get('/blocks', handler.list_blocks)
    app.router.add_get('/blocks/{block_id}', handler.fetch_block)

    app.router.add_get('/batches', handler.list_batches)
    app.router.add_get('/batches/{batch_id}', handler.fetch_batch)

    app.router.add_get('/transactions', handler.list_transactions)
    app.router.add_get(
        '/transactions/{transaction_id}',
        handler.fetch_transaction)

    app.router.add_get('/receipts', handler.list_receipts)
    app.router.add_post('/receipts', handler.list_receipts)

    app.router.add_get('/peers', handler.fetch_peers)
    app.router.add_get('/status', handler.fetch_status)

    subscriber_handler = StateDeltaSubscriberHandler(connection)
    app.router.add_get('/subscriptions', subscriber_handler.subscriptions)
    app.on_shutdown.append(lambda app: subscriber_handler.on_shutdown())

    # Start app
    LOGGER.info('Starting REST API on %s:%s', host, port)

    web.run_app(
        app,
        host=host,
        port=port,
        access_log=LOGGER,
        access_log_format='%r: %s status, %b size, in %Tf s')