code: def sc():
      return SparkContext._active_spark_context
  
imports: from pyspark import SparkContext
  from pyspark.sql.column import Column, _to_java_column, _to_seq
  from typeguard import check_argument_types, check_return_type
  from typing import Union
label_desc: Use image node_id 1 for calling a global function with example usage: sc() and returns: SparkContext