in safari 5. When the react project is run in the version, the variable Set does not exist. It is difficult for me to use all three methods

//
"plugins":[
"transform-runtime"
]

//

import "babel-polyfill"

//

import "core-js/es6/set"

I would like to ask the gods how to solve

also appears in ie11, the assign method is not easy to use, and the above method is not easy to use