<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_workspace(self, *parts) -> str: """Return a path to a private workspace dir. Create sub-tree of dirs using strings from `parts` inside workspace, and return full path to innermost directory. Upon returning successfully, the directory will exist (potentially changed to a safe FS name), even if it didn't exist before, including any intermediate parent directories. """

        workspace_dir = os.path.join(self.conf.get_workspace_path(),
                                     *(get_safe_path(part) for part in parts))
        if not os.path.isdir(workspace_dir):
            # exist_ok=True in case of concurrent creation of the same dir
            os.makedirs(workspace_dir, exist_ok=True)
        return workspace_dir