docs: def _determine_selected_stencil(stencil_set, stencil_definition):
      """Determine appropriate stencil name for stencil definition.
  
      Given a fastfood.json stencil definition with a stencil set, figure out
      what the name of the stencil within the set should be, or use the default
      """
      if 'stencil' not in stencil_definition:
          selected_stencil_name = stencil_set.manifest.get('default_stencil')
      else:
          selected_stencil_name = stencil_definition.get('stencil')
  
      if not selected_stencil_name:
          raise ValueError("No stencil name, within stencil set %s, specified."
                           % stencil_definition['name'])
  
      return selected_stencil_name