from docutils import nodes

       from docutils.parsers.rst import Directive

       from documenteer.sphinxext.utils import SphinxExtension

       # module-level instance. All members of the Sphinx extension refer to

       # this instance.

       extension = SphinxExtension()

       # Decorate a directive class to register it with the extension

       @extension.directive

       def MyDirective(Directive):

           # By putting a ``name`` attribute in your directive, SphinxExtension

           # will use that name for the directive name.

           name = "my-directive"

           def run(self):

               return [nodes.paragraph(text='Hello world')

        # Now your setup function just calls the setup method on the

        # SphinxExtension instance

        def setup():

            extension.setup()