code: function visit(state, filePath, one, done) {
    var file
  
    // Don’t walk into places multiple times.
    if (own.call(state.checked, filePath)) {
      done([])
      return
    }
  
    state.checked[filePath] = true
  
    file = vfile(filePath)
  
    stat(resolve(filePath), onstat)
  
    function onstat(error, stats) {
      var real = Boolean(stats)
      var results = []
      var result
  
      if (state.broken || !real) {
        done([])
      } else {
        result = state.test(file, stats)
  
        if (mask(result, INCLUDE)) {
          results.push(file)
  
          if (one) {
            state.broken = true
            return done(results)
          }
        }
  
        if (mask(result, BREAK)) {
          state.broken = true
        }
  
        if (state.broken || !stats.isDirectory() || mask(result, SKIP)) {
          return done(results)
        }
  
        readdir(filePath, onread)
      }
  
      function onread(error, entries) {
        visitAll(state, entries, filePath, one, onvisit)
      }
  
      function onvisit(files) {
        done(results.concat(files))
      }
    }
  }
docs: Find files in `filePath`.