Code blocks do not support the :linenos: directive

Please look at the following site for examples: [Directives/Showing Code Examples @ sphinx-doc.org](http://www.sphinx-doc.org/en/master/usage/restructuredtext/directives.html?highlight=line%20numbers#showing-code-examples)

E.g.:

.. code-block:: python
:linenos:

print("Hello World")

Read the linked Sphinx documentation and reproduce the provided reStructuredText code-block example in restview. Find where the code-block directive is handled, then verify that the :linenos: option produces line numbers for the displayed Python example.

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