code: def echo(x):
      return x
  
file_path: ipyparallel/ipyparallel/tests/test_executor.py
imports: import time
  from ipyparallel.client.view import LazyMapIterator, LoadBalancedView
  from .clienttest import ClusterTestCase
label_desc: Use image node_id 2 for calling a global function with example usage: echo(x) and returns: x