code: def _list_outputs(self):
      outputs = self.output_spec().get()
      outputs["track_file"] = os.path.abspath(self.inputs.output_file)
      if isdefined(self.inputs.output_mask) and self.inputs.output_mask:
          outputs["mask_file"] = os.path.abspath(
              self.inputs.output_mask
          )
  
      return outputs
  
imports: import os
  import re
  from ...utils.filemanip import fname_presuffix, split_filename, copyfile
  from ..base import TraitedSpec, File, traits, CommandLine, CommandLineInputSpec, isdefined
label_desc: Use image node_id 2 for calling the DTITracker obj's underlying member method code with example usage: obj._list_outputs() and returns: outputs