code: def last_day(date):
      
      sc = SparkContext._active_spark_context
      return Column(sc._jvm.functions.last_day(_to_java_column(date)))
docs: Returns the last day of the month which the given date belongs to.
  
      >>> df = spark.createDataFrame([('1997-02-10',)], ['d'])
      >>> df.select(last_day(df.d).alias('date')).collect()
      [Row(date=datetime.date(1997, 2, 28))]