
Create a buildout with the extension. The goal is to find the test requirement
extras for distribution pimp.

    >>> write(sample_buildout, 'buildout.cfg',
    ... """\
    ... [buildout]
    ... extensions = buildout.autoextras
    ... parts =
    ...     demo
    ... autoextra-keys =
    ...     test
    ...     config
    ... autoextra-targets =
    ...     demo:eggs
    ...
    ... [demo]
    ... recipe = zc.recipe.egg
    ... find-links = %(server)s
    ... index = %(server)s/index
    ... eggs = project
    ... """ % dict(server=link_server))
    >>> print system(buildout), #doctest: +ELLIPSIS
    Installing demo.
    Getting distribution for 'project'.
    Got project 1.0.
    Getting distribution for 'project-testing'.
    Got project-testing 1.0.
    warning: install_lib: 'build/lib' does not exist -- no Python modules to install
    warning: install_lib: 'build/lib' does not exist -- no Python modules to install

The requirement extra for pimp is babypowder, for softly bitch slapping tests of course. ;)

    >>> import os
    >>> ls(os.path.join(sample_buildout, 'eggs'))
    d  project-1.0-py2.6.egg
    d  project_testing-1.0-py2.6.egg
    -  setuptools.egg-link
    -  zc.buildout.egg-link
    -  zc.recipe.egg.egg-link

.. note:: i HATE zc.buildout!
