code: def hostname(self):
      import socket
  
      return socket.gethostname()
  
imports: import time
  import numpy
  import ray
  from bigdl.dllib.nncontext import init_spark_on_yarn
  from bigdl.orca.ray import OrcaRayContext
label_desc: Use image node_id 1 for calling the TestRay obj's underlying member method code with example usage: obj.hostname() and returns: socket