code: def create_noop_node():
      
      exe = wdax.Executable('NOOP')
      pfn = distutils.spawn.find_executable('true')
      exe.add_pfn(pfn)
      node = wdax.Node(exe)
      return node
docs: Creates a noop node that can be added to a DAX doing nothing. The reason
      for using this is if a minifollowups dax contains no triggers currently
      the dax will contain no jobs and be invalid. By adding a noop node we
      ensure that such daxes will actually run if one adds one such noop node.
      Adding such a noop node into a workflow *more than once* will cause a
      failure.