code: function visitAll(state, paths, cwd, one, done) {
    var expected = paths.length
    var actual = -1
    var result = []
  
    paths.forEach(each)
  
    next()
  
    function each(filePath) {
      visit(state, join(cwd || '', filePath), one, onvisit)
    }
  
    function onvisit(files) {
      result = result.concat(files)
      next()
    }
  
    function next() {
      actual++
  
      if (actual === expected) {
        done(result)
      }
    }
  }
docs: Find files in `paths`.  Returns a list of applicable files.