text: import parser from 'postcss-selector-parser'
  import tap from 'lodash/tap'
  
  export default function(prefix, selector) {
    const getPrefix = typeof prefix === 'function' ? prefix : () => prefix
  
    return parser(selectors => {
      selectors.walkClasses(classSelector => {
        tap(classSelector.value, baseClass => {
          classSelector.value = `${getPrefix('.' + baseClass)}${baseClass}`
        })
      })
    }).processSync(selector)
  }
  