def working_set(self, extra=()):
        options = self.options
        b_options = self.buildout['buildout']



        packages = self.opt_packages[:]
        orig_packages = packages[:]
        packages.extend(extra)

        if self.opt_offline:
            ws = easy_install.working_set(
                     packages,
                     self.opt_executable,
                     [
                         self.opt_develop_eggs_dir,
                         self.opt_eggs_dir
                     ],
                     include_site_packages=self.include_site_packages,
                     allowed_eggs_from_site_packages=self.allowed_eggs,
                )
        else:
            kw = {}
            if 'unzip' in options:
                kw['always_unzip'] = options.query_bool('unzip', None)
            ws = zc.buildout.easy_install.install(
                     packages,
                     self.opt_eggs_dir,
                     links=self.links,
                     index=self.index,
                     executable=self.opt_executable,
                     path=[self.opt_develop_eggs_dir],
                     newest=b_options.get('newest') == 'true',
                     include_site_packages=self.include_site_packages,
                     allowed_eggs_from_site_packages=self.allowed_eggs,
                     allow_hosts=self.allow_hosts,
                     **kw
                 )

        return orig_packages, ws
Separate method to just get the working set
dataset/ETHPy150Open moraes/tipfy/manage/newaction.py/InstallPackagesAction.working_set