class_docstr: Extends `BaseInterface` class to implement SPM specific interfaces.
  
  WARNING: Pseudo prototype class, meant to be subclassed
class_docstr_tok: ["Extends","`","BaseInterface","`","class","to","implement","SPM","specific","interfaces",".","WARNING",":","Pseudo","prototype","class",",","meant","to","be","subclassed"]
code: def _find_mlab_cmd_defaults(self):
      # check if the user has set environment variables to enforce
      # the standalone (MCR) version of SPM
      if self._use_mcr or "FORCE_SPMMCR" in os.environ:
          self._use_mcr = True
          if self._matlab_cmd is None:
              try:
                  self._matlab_cmd = os.environ["SPMMCRCMD"]
              except KeyError:
                  pass
  
imports: import os
  from copy import deepcopy
  from nibabel import load
  import numpy
  from ...None import logging
  from ...utils import spm_docs
  from ..base import BaseInterface, traits, isdefined, InputMultiPath, BaseInterfaceInputSpec, Directory, Undefined, ImageFile, PackageInfo
  from ..base.traits_extension import NoDefaultSpecified
  from ..matlab import MatlabCommand
  from ...external.due import due, Doi, BibTeX
label_desc: Use image node_id 3 for calling the SPMCommand obj's underlying member method code with example usage: obj._find_mlab_cmd_defaults() without return types