code: def setup(template_paths={}, autoescape=False, cache_size=100, auto_reload=True, bytecode_cache=True):
    
    global _jinja_env, _jinja_loaders
    
    if not _jinja_env:
      _jinja_env = JinjaEnviroment(
        autoescape=autoescape,
        cache_size=cache_size,
        auto_reload=auto_reload,
        bytecode_cache=None)
  
    # @TODO alter so Marshall is not used
    # if bytecode_cache and GAE_CACHE:
      # _jinja_env.bytecode_cache = GAEMemcacheBytecodeCache()
  
    if type(template_paths) == type(''):
      template_paths = {'site': template_paths}
    
    if len(template_paths) < 1:
      logging.exception('Sketch: jinja.setup: no template sets configured')
      return False
  
    if len(template_paths) == 1:
      template_set_name = template_paths.keys()[0]
      tp = template_paths[template_set_name]
      if tp in _jinja_loaders:
        _jinja_env.loader = _jinja_loaders[tp]
      else:
        _jinja_env.loader = _jinja_loaders[tp] = jinja2.FileSystemLoader(tp)
      return True
        
    if len(template_paths) > 1:
      loaders = {}
      for dirn, path in template_paths.items():
        loaders[dirn] = jinja2.FileSystemLoader(path)
      _jinja_env.loader = SubdirLoader(loaders)
      return True
    logging.error('Sketch: jinja.setup: no template sets configured (fallthrough)')
    logging.error(_jinja_loaders)
docs: Setup Jinja enviroment
    
    eg. sketch.jinja.setup({
        'app': self.config.paths['app_template_basedir'],
        'sketch': self.config.paths['sketch_template_dir'],
      })
    
    :param template_paths: Dictionary of paths to templates (template_name => template_path)
    :param autoescape: Autoescape
    :param cache_size:
    :param auto_reload:
    :param bytecode_cache: