class_docstr: Generates a ROI file for connectivity mapping and a dictionary file containing relevant node information
  
  Example
  -------
  
  >>> import nipype.interfaces.cmtk as cmtk
  >>> rg = cmtk.ROIGen()
  >>> rg.inputs.aparc_aseg_file = 'aparc+aseg.nii'
  >>> rg.inputs.use_freesurfer_LUT = True
  >>> rg.inputs.freesurfer_dir = '/usr/local/freesurfer'
  >>> rg.run() # doctest: +SKIP
  
  The label dictionary is written to disk using Pickle. Resulting data can be loaded using:
  
  >>> file = open("FreeSurferColorLUT_adapted_aparc+aseg_out.pck", "r")
  >>> file = open("fsLUT_aparc+aseg.pck", "r")
  >>> labelDict = pickle.load(file) # doctest: +SKIP
  >>> labelDict                     # doctest: +SKIP
code: def _gen_outfilename(self, ext):
      _, name, _ = split_filename(self.inputs.aparc_aseg_file)
      if self.inputs.use_freesurfer_LUT:
          prefix = "fsLUT"
      elif not self.inputs.use_freesurfer_LUT and isdefined(
          self.inputs.LUT_file
      ):
          lutpath, lutname, lutext = split_filename(
              self.inputs.LUT_file
          )
          prefix = lutname
      else:
          prefix = "hardcoded"
      return prefix + "_" + name + "." + ext
  
imports: import pickle
  import os.path
  import numpy
  import nibabel
  import networkx
  from ...None import logging
  from ...utils.filemanip import split_filename
  from ..base import BaseInterface, BaseInterfaceInputSpec, traits, File, TraitedSpec, Directory, OutputMultiPath, isdefined
label_desc: Use image node_id 3 for calling the ROIGen obj's underlying member method code with example usage: obj._gen_outfilename(ext) and returns: unknown