code: def defaults_cluster_role_env(cluster_role_env):
    
    if len(cluster_role_env[1]) == 0 and len(cluster_role_env[2]) == 0:
      return (cluster_role_env[0], getpass.getuser(), ENVIRON)
  
    return (cluster_role_env[0], cluster_role_env[1], cluster_role_env[2])
docs: if role is not provided, supply userid
    if environ is not provided, supply 'default'