code: def from_packages(cls, parse_context, rev='', packages=None, **kwargs):
      
      for pkg in packages or ('',):
        cls.from_package(parse_context, pkg=pkg, rev=rev, **kwargs)
docs: :param list packages: The package import paths within the remote library; by default just the
                            root package will be available (equivalent to passing `packages=['']`).
      :param string rev: Identifies which version of the remote library to download. This could be a
                         commit SHA (git), node id (hg), etc.  If left unspecified the version will
                         default to the latest available.  It's highly recommended to not accept the
                         default and instead pin the rev explicitly for repeatable builds.