code: def init_spark_on_local(self, cores, conf=None, python_location=None):
      print("Start to getOrCreate SparkContext")
      if "PYSPARK_PYTHON" not in os.environ:
          os.environ["PYSPARK_PYTHON"] = (
              python_location
              if python_location
              else detect_python_location()
          )
      master = "local[{}]".format(cores)
      zoo_conf = init_spark_conf(conf).setMaster(master)
      sc = init_nncontext(
          conf=zoo_conf,
          spark_log_level=self.spark_log_level,
          redirect_spark_log=self.redirect_spark_log,
      )
      print("Successfully got a SparkContext")
      return sc
  
file_path: analytics-zoo/pyzoo/zoo/util/spark.py
imports: import os
  import platform
  from pyspark import SparkContext
  from zoo import init_nncontext, init_spark_conf
  from zoo.util.utils import detect_python_location, pack_penv
  from zoo.util.utils import get_executor_conda_zoo_classpath, get_zoo_bigdl_classpath_on_driver
label_desc: Use image node_id 3 for calling the SparkRunner obj's underlying member method code with example usage: obj.init_spark_on_local(cores, conf, python_location) and returns: sc