code: def set_model_pathnames(self):
          
          self.control_path = self.expt.control_path
          self.input_basepath = self.expt.lab.input_basepath
          self.work_path = self.expt.work_path
          self.codebase_path = self.expt.lab.codebase_path
  
          if len(self.expt.models) > 1:
  
              self.control_path = os.path.join(self.control_path, self.name)
              self.work_path = os.path.join(self.work_path, self.name)
              self.codebase_path = os.path.join(self.codebase_path, self.name)
  
          # NOTE: Individual models may override the work subdirectories
          self.work_input_path = self.work_path
          self.work_restart_path = self.work_path
          self.work_output_path = self.work_path
          self.work_init_path = self.work_path
  
          self.exec_prefix = self.config.get('exe_prefix', '')
          self.exec_name = self.config.get('exe', self.default_exec)
          if self.exec_name:
              # By default os.path.join will not prepend the lab bin_path
              # to an absolute path
              self.exec_path = os.path.join(self.expt.lab.bin_path,
                                            self.exec_name)
          else:
              self.exec_path = None
  
          if self.exec_path:
              # Make exec_name consistent for models with fully qualified path.
              # In all cases it will just be the name of the executable without a
              # path
              self.exec_name = os.path.basename(self.exec_path)
docs: Define the paths associated with this model.