code: def _get_gdcmconv():
      
      gdcmconv_executable = settings.gdcmconv_path
      if gdcmconv_executable is None:
          gdcmconv_executable = _which('gdcmconv')
      if gdcmconv_executable is None:
          gdcmconv_executable = _which('gdcmconv.exe')
  
      if gdcmconv_executable is None:
          raise ConversionError('GDCMCONV_NOT_FOUND')
  
      return gdcmconv_executable
docs: Get the full path to gdcmconv.
      If not found raise error