code: def load(self, steps_dir=None, step_file=None, step_list=None):
          
          self._closed()
  
          self.steps_library.load(steps_dir=steps_dir, step_file=step_file,
                                  step_list=step_list)
docs: Load CWL steps into the WorkflowGenerator's steps library.
  
          Adds steps (command line tools and workflows) to the
          ``WorkflowGenerator``'s steps library. These steps can be used to
          create workflows.
  
          Args:
              steps_dir (str): path to directory containing CWL files. All CWL in
                  the directory are loaded.
              step_file (str): path to a file containing a CWL step that will be
                  added to the steps library.