code: def install(self, release_id):
          
          release_path = os.path.join(self._releases, release_id)
          if not self._runner.exists(release_path):
              self._runner.run("mkdir -p '{0}'".format(release_path))
  
          # The artifact can optionally be renamed to something specific when
          # downloaded on the remote server. In that case use the provided name
          # in the download path. Otherwise, just use the last component of
          # of the URL we're downloading.
          if self._remote_name is not None:
              destination = os.path.join(release_path, self._remote_name)
          else:
              destination = os.path.join(release_path, self._get_file_from_url(self._artifact_url))
  
          # Note that although the default implementation of a download method
          # accepts a FabRunner instance, we aren't passing our instance here.
          # The reason being, that's only needed for testing the download_url
          # method. If we were testing class, we'd mock out the download method
          # anyway. So, it's not part of the public API of the download interface
          # and we don't deal with it here.
          return self._downloader(
              self._artifact_url,
              destination,
              retries=self._retries,
              retry_delay=self._retry_delay
          )
docs: Download and install an artifact into the remote release directory,
          optionally with a different name the the artifact had.
  
          If the directory for the given release ID does not exist on the remote
          system, it will be created. The directory will be created according to
          the standard Tunic directory structure (see :doc:`design`).
  
          :param str release_id: Timestamp-based identifier for this deployment.
          :return: The results of the download function being run. This return value
              should be the result of running a command with Fabric. By default
              this will be the result of running ``wget``.