code: def perform_exe_expansion(self):
          
          # Only works on executables section
          if self.has_section('executables'):
              for option, value in self.items('executables'):
                  # Check the value
                  newStr = self.interpolate_exe(value)
                  if newStr != value:
                      self.set('executables', option, newStr)
docs: This function will look through the executables section of the
          ConfigParser object and replace any values using macros with full paths.
  
          For any values that look like
  
          ${which:lalapps_tmpltbank}
  
          will be replaced with the equivalent of which(lalapps_tmpltbank)
  
          Otherwise values will be unchanged.