code: def working_set(self, extra=()):
          
          options = self.options
          b_options = self.buildout['buildout']
  
          # Backward compat. :(
          options['executable'] = sys.executable
  
          distributions = [
              r.strip()
              for r in options.get('eggs', self.name).split('\n')
              if r.strip()]
          orig_distributions = distributions[:]
          distributions.extend(extra)
  
          if self.buildout['buildout'].get('offline') == 'true':
              ws = zc.buildout.easy_install.working_set(
                  distributions,
                  [options['develop-eggs-directory'], options['eggs-directory']]
                  )
          else:
              ws = zc.buildout.easy_install.install(
                  distributions, options['eggs-directory'],
                  links=self.links,
                  index=self.index,
                  path=[options['develop-eggs-directory']],
                  newest=self.buildout['buildout'].get('newest') == 'true',
                  allow_hosts=self.allow_hosts)
  
          return orig_distributions, ws
docs: Separate method to just get the working set
  
          This is intended for reuse by similar recipes.