code: def _setup(self):
          
          log.info("Creating virtualenv for {0}".format(self.name))
          util.check_call([
              sys.executable,
              "-mvirtualenv",
              '--no-site-packages',
              "-p",
              self._executable,
              self._path])
  
          log.info("Installing requirements for {0}".format(self.name))
          self._install_requirements()
docs: Setup the environment on disk using virtualenv.
          Then, all of the requirements are installed into
          it using `pip install`.