function pluginCreator() {
  return {
    postcssPlugin: 'postcss-plugin-stub',
    prepare() {
      return {}
    },
  }
}
This file creates a stub postcss plugin

It will be pre-compiled into "src/compiled/postcss-plugin-stub-for-cssnano-simple",
which "postcss-svgo" will be aliased to when creating "cssnano-preset-simple"