How to get current compilation stage for processAssets hook?

I'm writing asynchronous plugin which could add assets at different stages and I need to compare current compilation stage to needed, is there a way I can get compilation stage for example, I need

apply(compiler) {
    compiler.hooks.thisCompilation.tap("TestWebpackPlugin", (compilation) => {
      compilation.hooks.processAssets.tap(
      //console.log(compilation.currentStage)
        { name: "TestWebpackPlugin", stage: undefined }, //some stage here
        () => {
          //console.log(compilation.currentStage)
        }
      );
    });
  }