code: def package_releases(request, package_name, show_hidden=False):
      
      session = DBSession()
      package = Package.by_name(session, package_name)
      return [rel.version for rel in package.sorted_releases]
docs: Retrieve a list of the releases registered for the given package_name.
      Returns a list with all version strings if show_hidden is True or
      only the non-hidden ones otherwise.