def extendMarkdown(self, md, md_globals):

        md.preprocessors.add('fenced_code_block', 
                                 FencedBlockPreprocessor(md), 
                                 "_begin")
Add FencedBlockPreprocessor to the Markdown instance.
dataset/ETHPy150Open natestedman/Observatory/observatory/lib/markdown/extensions/fenced_code.py/FencedCodeExtension.extendMarkdown