Consider this simplified streaming code snippet using Kafka and Spark in a Kappa architecture:

Consider this simplified streaming code snippet using Kafka and Spark in a Kappa architecture:

from pyspark.sql import SparkSession
spark = SparkSession.builder.appName('KappaExample').getOrCreate()

# Read stream from Kafka topic
stream_df = spark.readStream.format('kafka') \
  .option('kafka.bootstrap.servers', 'localhost:9092') \
  .option('subscribe', 'events') \
  .load()

# Select and cast value to string
value_df = stream_df.selectExpr('CAST(value AS STRING)')

# Write stream to console
query = value_df.writeStream.outputMode('append').format('console').start()

query.awaitTermination()

What will this code do?