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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def load(self, steps_dir=None, step_file=None, step_list=None):
 """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. """

        self._closed()

        self.steps_library.load(steps_dir=steps_dir, step_file=step_file,
                                step_list=step_list)