.. invisible-code-block: python

  run = []

Let's skips some stuff:

.. skip: next
.. code-block:: python

  run.append(1)

This one should run:

.. invisible-code-block: python

  run.append(2)

.. skip: start

These should not:

.. code-block:: python

  run.append(3)

Nor this one:

.. code-block:: python

  run.append(4)

.. skip: end

But this one should:

.. code-block:: python

  run.append(5)
