code: def sort_array(col, asc=True):
      
      sc = SparkContext._active_spark_context
      return Column(sc._jvm.functions.sort_array(_to_java_column(col), asc))
docs: Collection function: sorts the input array in ascending or descending order according
      to the natural ordering of the array elements. Null elements will be placed at the beginning
      of the returned array in ascending order or at the end of the returned array in descending
      order.
  
      :param col: name of column or expression
  
      >>> df = spark.createDataFrame([([2, 1, None, 3],),([1],),([],)], ['data'])
      >>> df.select(sort_array(df.data).alias('r')).collect()
      [Row(r=[None, 1, 2, 3]), Row(r=[1]), Row(r=[])]
      >>> df.select(sort_array(df.data, asc=False).alias('r')).collect()
      [Row(r=[3, 2, 1, None]), Row(r=[1]), Row(r=[])]