code: def get_default_args(func):
      """Return optional arguments of a function.
  
      Parameters
      ----------
      func: callable
  
      Returns
      -------
      dict
  
      """
      signature = inspect.signature(func)
      return {
          k: v.default
          for k, v in signature.parameters.items()
          if v.default is not inspect.Parameter.empty
      }
  
file_path: nipype/nipype/interfaces/dipy/base.py
imports: import os.path
  import inspect
  import numpy
  from ...None import logging
  from ..base import traits, File, isdefined, LibraryBaseInterface, BaseInterfaceInputSpec, TraitedSpec
label_desc: Use image node_id 3 for calling a global function with example usage: get_default_args(func) and returns: unknown