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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 _create_target_tree(self, target):
 """ There is a bug in dir_util that makes `copy_tree` crash if a folder in the tree has been deleted before and readded now. To workaround the bug, we first walk the tree and create directories that are needed. """

        source = self
        with source.walker as walker:

            @walker.folder_visitor
            def visit_folder(folder):
                """
                Create the mirror directory
                """
                if folder != source:
                    Folder(folder.get_mirror(target, source)).make()