code: def _remove_nonjoin_identity_nodes(graph, keep_iterables=False):
      """Remove non-join identity nodes from the given graph
  
      Iterable nodes are retained if and only if the keep_iterables
      flag is set to True.
      """
      # if keep_iterables is False, then include the iterable
      # and join nodes in the nodes to delete
      for node in _identity_nodes(graph, not keep_iterables):
          if not hasattr(node, "joinsource"):
              _remove_identity_node(graph, node)
      return graph
  
imports: import os
  import sys
  import pickle
  from collections import defaultdict
  import re
  from copy import deepcopy
  from glob import glob
  from pathlib import Path
  from traceback import format_exception
  from hashlib import sha1
  from functools import reduce
  import numpy
  from ...None import logging, config
  from ...utils.filemanip import indirectory, relpath, fname_presuffix, ensure_list, get_related_files, save_json, savepkl, loadpkl, write_rst_header, write_rst_dict, write_rst_list
  from ...utils.misc import str2bool
  from ...utils.functions import create_function_from_source
  from ...interfaces.base.traits_extension import rebase_path_traits, resolve_path_traits, OutputMultiPath, isdefined, Undefined
  from ...interfaces.base.support import Bunch, InterfaceResult
  from ...interfaces.base import CommandLine
  from ...interfaces.utility import IdentityInterface
  from ...utils.provenance import ProvStore, pm, nipype_ns, get_id
  from inspect import signature
label_desc: Use image node_id 25 for calling a global function with example usage: _remove_nonjoin_identity_nodes(graph, keep_iterables) and returns: graph