code: def hadoop_namenode():
      return os.getenv("NAME_NODE")
  
file_path: h2o-3/h2o-hadoop-common/tests_fault_tolerance/python/fault_tolerance_utils.py
imports: import os
  import subprocess
  from subprocess import PIPE, STDOUT, CalledProcessError
label_desc: Use image node_id 1 for calling a global function with example usage: hadoop_namenode() and returns: os